• Privacy Policy

Research Method

Home » Quasi-Experimental Research Design – Types, Methods

Quasi-Experimental Research Design – Types, Methods

Table of Contents

Quasi-experimental research design is a widely used methodology in social sciences, education, healthcare, and other fields to evaluate the impact of an intervention or treatment. Unlike true experimental designs, quasi-experiments lack random assignment, which can limit control over external factors but still offer valuable insights into cause-and-effect relationships.

This article delves into the concept of quasi-experimental research, explores its types, methods, and applications, and discusses its strengths and limitations.

Quasi-Experimental Design

Quasi-Experimental Design

Quasi-experimental research design is a type of empirical study used to estimate the causal relationship between an intervention and its outcomes. It resembles an experimental design but does not involve random assignment of participants to groups. Instead, groups are pre-existing or assigned based on non-random criteria, such as location, demographic characteristics, or convenience.

For example, a school might implement a new teaching method in one class while another class continues with the traditional approach. Researchers can then compare the outcomes to assess the effectiveness of the new method.

Key Characteristics of Quasi-Experimental Research

  • No Random Assignment: Participants are not randomly assigned to experimental or control groups.
  • Comparison Groups: Often involves comparing a treatment group to a non-equivalent control group.
  • Real-World Settings: Frequently conducted in natural environments, such as schools, hospitals, or workplaces.
  • Causal Inference: Aims to identify causal relationships, though less robustly than true experiments.

Purpose of Quasi-Experimental Research

  • To evaluate interventions or treatments when randomization is impractical or unethical.
  • To provide evidence of causality in real-world settings.
  • To test hypotheses and inform policies or practices.

Types of Quasi-Experimental Research Design

1. non-equivalent groups design (negd).

In this design, the researcher compares outcomes between a treatment group and a control group that are not randomly assigned.

  • Example: Comparing student performance in schools that adopt a new curriculum versus those that do not.
  • Limitation: Potential selection bias due to differences between the groups.

2. Time-Series Design

This involves repeatedly measuring the outcome variable before and after the intervention to observe trends over time.

  • Example: Monitoring air pollution levels before and after implementing an industrial emission regulation.
  • Variation: Interrupted time-series design, which identifies significant changes at specific intervention points.

3. Regression Discontinuity Design (RDD)

Participants are assigned to treatment or control groups based on a predetermined cutoff score on a continuous variable.

  • Example: Evaluating the effect of a scholarship program where students with test scores above a threshold receive funding.
  • Strength: Stronger causal inference compared to other quasi-experimental designs.

4. Pretest-Posttest Design

In this design, outcomes are measured before and after the intervention within the same group.

  • Example: Assessing the effectiveness of a training program by comparing employees’ skills before and after the training.
  • Limitation: Vulnerable to confounding factors that may influence results independently of the intervention.

5. Propensity Score Matching (PSM)

This method pairs participants in the treatment and control groups based on similar characteristics to reduce selection bias.

  • Example: Evaluating the impact of online learning by matching students based on demographics and prior academic performance.
  • Strength: Improves comparability between groups.

Methods of Quasi-Experimental Research

1. data collection.

  • Surveys: Collect information on attitudes, behaviors, or outcomes related to the intervention.
  • Observations: Document changes in natural environments or behaviors over time.
  • Archival Data: Use pre-existing data, such as medical records or academic scores, to analyze outcomes.

2. Statistical Analysis

Quasi-experiments rely on statistical techniques to control for confounding variables and enhance the validity of results.

  • Analysis of Covariance (ANCOVA): Controls for pre-existing differences between groups.
  • Regression Analysis: Identifies relationships between the intervention and outcomes while accounting for other factors.
  • Propensity Score Matching: Balances treatment and control groups to reduce bias.

3. Control for Confounding Variables

Because randomization is absent, quasi-experimental designs must address confounders using techniques like:

  • Matching: Pair participants with similar attributes.
  • Stratification: Analyze subgroups based on characteristics like age or income.
  • Sensitivity Analysis: Test how robust findings are to potential biases.

4. Use of Mixed Methods

Combining quantitative and qualitative methods enhances the depth of analysis.

  • Quantitative: Statistical tests to measure effect size.
  • Qualitative: Interviews or focus groups to understand contextual factors influencing outcomes.

Applications of Quasi-Experimental Research

1. education.

  • Assessing the impact of new teaching methods or curricula.
  • Evaluating the effectiveness of after-school programs on academic performance.

2. Healthcare

  • Comparing outcomes of different treatment protocols in hospitals.
  • Studying the impact of public health campaigns on vaccination rates.

3. Policy Analysis

  • Measuring the effects of new laws or regulations, such as minimum wage increases.
  • Evaluating the impact of urban planning initiatives on community health.

4. Social Sciences

  • Studying the influence of community programs on crime rates.
  • Analyzing the effect of workplace interventions on employee satisfaction.

Strengths of Quasi-Experimental Research

  • Feasibility: Can be conducted in real-world settings where randomization is impractical or unethical.
  • Cost-Effectiveness: Often requires fewer resources compared to true experiments.
  • Flexibility: Accommodates a variety of contexts and research questions.
  • Generates Evidence: Provides valuable insights into causal relationships.

Limitations of Quasi-Experimental Research

  • Potential Bias: Lack of randomization increases the risk of selection bias.
  • Confounding Variables: Results may be influenced by external factors unrelated to the intervention.
  • Limited Generalizability: Findings may not apply broadly due to non-random group assignment.
  • Weaker Causality: Less robust in establishing causation compared to randomized controlled trials.

Steps to Conduct Quasi-Experimental Research

  • Define the Research Question: Clearly articulate what you aim to study and why a quasi-experimental design is appropriate.
  • Identify Comparison Groups: Select treatment and control groups based on the research context.
  • Collect Data: Use surveys, observations, or archival records to gather pre- and post-intervention data.
  • Control for Confounders: Employ statistical methods or matching techniques to address potential biases.
  • Analyze Results: Use appropriate statistical tools to evaluate the intervention’s impact.
  • Interpret Findings: Discuss results in light of limitations and potential confounding factors.

Quasi-experimental research design offers a practical and versatile approach for evaluating interventions when randomization is not feasible. By employing methods such as non-equivalent groups design, time-series analysis, and regression discontinuity, researchers can draw meaningful conclusions about causal relationships. While these designs may have limitations in controlling bias and confounding variables, careful planning, robust statistical techniques, and clear reporting can enhance their validity and impact. Quasi-experiments are invaluable in fields like education, healthcare, and policy analysis, providing actionable insights for real-world challenges.

  • Cook, T. D., & Campbell, D. T. (1979). Quasi-Experimentation: Design and Analysis Issues for Field Settings . Houghton Mifflin.
  • Shadish, W. R., Cook, T. D., & Campbell, D. T. (2002). Experimental and Quasi-Experimental Designs for Generalized Causal Inference . Houghton Mifflin.
  • Creswell, J. W. (2018). Research Design: Qualitative, Quantitative, and Mixed Methods Approaches . Sage Publications.
  • Bryman, A. (2016). Social Research Methods . Oxford University Press.
  • Babbie, E. (2020). The Practice of Social Research . Cengage Learning.

About the author

' src=

Muhammad Hassan

Researcher, Academic Writer, Web developer

You may also like

Transformative Design

Transformative Design – Methods, Types, Guide

Exploratory Research

Exploratory Research – Types, Methods and...

Observational Research

Observational Research – Methods and Guide

Research Methods

Research Methods – Types, Examples and Guide

Mixed Research methods

Mixed Methods Research – Types & Analysis

Ethnographic Research

Ethnographic Research -Types, Methods and Guide

Logo for M Libraries Publishing

Want to create or adapt books like this? Learn more about how Pressbooks supports open publishing practices.

7.3 Quasi-Experimental Research

Learning objectives.

  • Explain what quasi-experimental research is and distinguish it clearly from both experimental and correlational research.
  • Describe three different types of quasi-experimental research designs (nonequivalent groups, pretest-posttest, and interrupted time series) and identify examples of each one.

The prefix quasi means “resembling.” Thus quasi-experimental research is research that resembles experimental research but is not true experimental research. Although the independent variable is manipulated, participants are not randomly assigned to conditions or orders of conditions (Cook & Campbell, 1979). Because the independent variable is manipulated before the dependent variable is measured, quasi-experimental research eliminates the directionality problem. But because participants are not randomly assigned—making it likely that there are other differences between conditions—quasi-experimental research does not eliminate the problem of confounding variables. In terms of internal validity, therefore, quasi-experiments are generally somewhere between correlational studies and true experiments.

Quasi-experiments are most likely to be conducted in field settings in which random assignment is difficult or impossible. They are often conducted to evaluate the effectiveness of a treatment—perhaps a type of psychotherapy or an educational intervention. There are many different kinds of quasi-experiments, but we will discuss just a few of the most common ones here.

Nonequivalent Groups Design

Recall that when participants in a between-subjects experiment are randomly assigned to conditions, the resulting groups are likely to be quite similar. In fact, researchers consider them to be equivalent. When participants are not randomly assigned to conditions, however, the resulting groups are likely to be dissimilar in some ways. For this reason, researchers consider them to be nonequivalent. A nonequivalent groups design , then, is a between-subjects design in which participants have not been randomly assigned to conditions.

Imagine, for example, a researcher who wants to evaluate a new method of teaching fractions to third graders. One way would be to conduct a study with a treatment group consisting of one class of third-grade students and a control group consisting of another class of third-grade students. This would be a nonequivalent groups design because the students are not randomly assigned to classes by the researcher, which means there could be important differences between them. For example, the parents of higher achieving or more motivated students might have been more likely to request that their children be assigned to Ms. Williams’s class. Or the principal might have assigned the “troublemakers” to Mr. Jones’s class because he is a stronger disciplinarian. Of course, the teachers’ styles, and even the classroom environments, might be very different and might cause different levels of achievement or motivation among the students. If at the end of the study there was a difference in the two classes’ knowledge of fractions, it might have been caused by the difference between the teaching methods—but it might have been caused by any of these confounding variables.

Of course, researchers using a nonequivalent groups design can take steps to ensure that their groups are as similar as possible. In the present example, the researcher could try to select two classes at the same school, where the students in the two classes have similar scores on a standardized math test and the teachers are the same sex, are close in age, and have similar teaching styles. Taking such steps would increase the internal validity of the study because it would eliminate some of the most important confounding variables. But without true random assignment of the students to conditions, there remains the possibility of other important confounding variables that the researcher was not able to control.

Pretest-Posttest Design

In a pretest-posttest design , the dependent variable is measured once before the treatment is implemented and once after it is implemented. Imagine, for example, a researcher who is interested in the effectiveness of an antidrug education program on elementary school students’ attitudes toward illegal drugs. The researcher could measure the attitudes of students at a particular elementary school during one week, implement the antidrug program during the next week, and finally, measure their attitudes again the following week. The pretest-posttest design is much like a within-subjects experiment in which each participant is tested first under the control condition and then under the treatment condition. It is unlike a within-subjects experiment, however, in that the order of conditions is not counterbalanced because it typically is not possible for a participant to be tested in the treatment condition first and then in an “untreated” control condition.

If the average posttest score is better than the average pretest score, then it makes sense to conclude that the treatment might be responsible for the improvement. Unfortunately, one often cannot conclude this with a high degree of certainty because there may be other explanations for why the posttest scores are better. One category of alternative explanations goes under the name of history . Other things might have happened between the pretest and the posttest. Perhaps an antidrug program aired on television and many of the students watched it, or perhaps a celebrity died of a drug overdose and many of the students heard about it. Another category of alternative explanations goes under the name of maturation . Participants might have changed between the pretest and the posttest in ways that they were going to anyway because they are growing and learning. If it were a yearlong program, participants might become less impulsive or better reasoners and this might be responsible for the change.

Another alternative explanation for a change in the dependent variable in a pretest-posttest design is regression to the mean . This refers to the statistical fact that an individual who scores extremely on a variable on one occasion will tend to score less extremely on the next occasion. For example, a bowler with a long-term average of 150 who suddenly bowls a 220 will almost certainly score lower in the next game. Her score will “regress” toward her mean score of 150. Regression to the mean can be a problem when participants are selected for further study because of their extreme scores. Imagine, for example, that only students who scored especially low on a test of fractions are given a special training program and then retested. Regression to the mean all but guarantees that their scores will be higher even if the training program has no effect. A closely related concept—and an extremely important one in psychological research—is spontaneous remission . This is the tendency for many medical and psychological problems to improve over time without any form of treatment. The common cold is a good example. If one were to measure symptom severity in 100 common cold sufferers today, give them a bowl of chicken soup every day, and then measure their symptom severity again in a week, they would probably be much improved. This does not mean that the chicken soup was responsible for the improvement, however, because they would have been much improved without any treatment at all. The same is true of many psychological problems. A group of severely depressed people today is likely to be less depressed on average in 6 months. In reviewing the results of several studies of treatments for depression, researchers Michael Posternak and Ivan Miller found that participants in waitlist control conditions improved an average of 10 to 15% before they received any treatment at all (Posternak & Miller, 2001). Thus one must generally be very cautious about inferring causality from pretest-posttest designs.

Does Psychotherapy Work?

Early studies on the effectiveness of psychotherapy tended to use pretest-posttest designs. In a classic 1952 article, researcher Hans Eysenck summarized the results of 24 such studies showing that about two thirds of patients improved between the pretest and the posttest (Eysenck, 1952). But Eysenck also compared these results with archival data from state hospital and insurance company records showing that similar patients recovered at about the same rate without receiving psychotherapy. This suggested to Eysenck that the improvement that patients showed in the pretest-posttest studies might be no more than spontaneous remission. Note that Eysenck did not conclude that psychotherapy was ineffective. He merely concluded that there was no evidence that it was, and he wrote of “the necessity of properly planned and executed experimental studies into this important field” (p. 323). You can read the entire article here:

http://psychclassics.yorku.ca/Eysenck/psychotherapy.htm

Fortunately, many other researchers took up Eysenck’s challenge, and by 1980 hundreds of experiments had been conducted in which participants were randomly assigned to treatment and control conditions, and the results were summarized in a classic book by Mary Lee Smith, Gene Glass, and Thomas Miller (Smith, Glass, & Miller, 1980). They found that overall psychotherapy was quite effective, with about 80% of treatment participants improving more than the average control participant. Subsequent research has focused more on the conditions under which different types of psychotherapy are more or less effective.

Han Eysenck

In a classic 1952 article, researcher Hans Eysenck pointed out the shortcomings of the simple pretest-posttest design for evaluating the effectiveness of psychotherapy.

Wikimedia Commons – CC BY-SA 3.0.

Interrupted Time Series Design

A variant of the pretest-posttest design is the interrupted time-series design . A time series is a set of measurements taken at intervals over a period of time. For example, a manufacturing company might measure its workers’ productivity each week for a year. In an interrupted time series-design, a time series like this is “interrupted” by a treatment. In one classic example, the treatment was the reduction of the work shifts in a factory from 10 hours to 8 hours (Cook & Campbell, 1979). Because productivity increased rather quickly after the shortening of the work shifts, and because it remained elevated for many months afterward, the researcher concluded that the shortening of the shifts caused the increase in productivity. Notice that the interrupted time-series design is like a pretest-posttest design in that it includes measurements of the dependent variable both before and after the treatment. It is unlike the pretest-posttest design, however, in that it includes multiple pretest and posttest measurements.

Figure 7.5 “A Hypothetical Interrupted Time-Series Design” shows data from a hypothetical interrupted time-series study. The dependent variable is the number of student absences per week in a research methods course. The treatment is that the instructor begins publicly taking attendance each day so that students know that the instructor is aware of who is present and who is absent. The top panel of Figure 7.5 “A Hypothetical Interrupted Time-Series Design” shows how the data might look if this treatment worked. There is a consistently high number of absences before the treatment, and there is an immediate and sustained drop in absences after the treatment. The bottom panel of Figure 7.5 “A Hypothetical Interrupted Time-Series Design” shows how the data might look if this treatment did not work. On average, the number of absences after the treatment is about the same as the number before. This figure also illustrates an advantage of the interrupted time-series design over a simpler pretest-posttest design. If there had been only one measurement of absences before the treatment at Week 7 and one afterward at Week 8, then it would have looked as though the treatment were responsible for the reduction. The multiple measurements both before and after the treatment suggest that the reduction between Weeks 7 and 8 is nothing more than normal week-to-week variation.

Figure 7.5 A Hypothetical Interrupted Time-Series Design

A Hypothetical Interrupted Time-Series Design - The top panel shows data that suggest that the treatment caused a reduction in absences. The bottom panel shows data that suggest that it did not

The top panel shows data that suggest that the treatment caused a reduction in absences. The bottom panel shows data that suggest that it did not.

Combination Designs

A type of quasi-experimental design that is generally better than either the nonequivalent groups design or the pretest-posttest design is one that combines elements of both. There is a treatment group that is given a pretest, receives a treatment, and then is given a posttest. But at the same time there is a control group that is given a pretest, does not receive the treatment, and then is given a posttest. The question, then, is not simply whether participants who receive the treatment improve but whether they improve more than participants who do not receive the treatment.

Imagine, for example, that students in one school are given a pretest on their attitudes toward drugs, then are exposed to an antidrug program, and finally are given a posttest. Students in a similar school are given the pretest, not exposed to an antidrug program, and finally are given a posttest. Again, if students in the treatment condition become more negative toward drugs, this could be an effect of the treatment, but it could also be a matter of history or maturation. If it really is an effect of the treatment, then students in the treatment condition should become more negative than students in the control condition. But if it is a matter of history (e.g., news of a celebrity drug overdose) or maturation (e.g., improved reasoning), then students in the two conditions would be likely to show similar amounts of change. This type of design does not completely eliminate the possibility of confounding variables, however. Something could occur at one of the schools but not the other (e.g., a student drug overdose), so students at the first school would be affected by it while students at the other school would not.

Finally, if participants in this kind of design are randomly assigned to conditions, it becomes a true experiment rather than a quasi experiment. In fact, it is the kind of experiment that Eysenck called for—and that has now been conducted many times—to demonstrate the effectiveness of psychotherapy.

Key Takeaways

  • Quasi-experimental research involves the manipulation of an independent variable without the random assignment of participants to conditions or orders of conditions. Among the important types are nonequivalent groups designs, pretest-posttest, and interrupted time-series designs.
  • Quasi-experimental research eliminates the directionality problem because it involves the manipulation of the independent variable. It does not eliminate the problem of confounding variables, however, because it does not involve random assignment to conditions. For these reasons, quasi-experimental research is generally higher in internal validity than correlational studies but lower than true experiments.
  • Practice: Imagine that two college professors decide to test the effect of giving daily quizzes on student performance in a statistics course. They decide that Professor A will give quizzes but Professor B will not. They will then compare the performance of students in their two sections on a common final exam. List five other variables that might differ between the two sections that could affect the results.

Discussion: Imagine that a group of obese children is recruited for a study in which their weight is measured, then they participate for 3 months in a program that encourages them to be more active, and finally their weight is measured again. Explain how each of the following might affect the results:

  • regression to the mean
  • spontaneous remission

Cook, T. D., & Campbell, D. T. (1979). Quasi-experimentation: Design & analysis issues in field settings . Boston, MA: Houghton Mifflin.

Eysenck, H. J. (1952). The effects of psychotherapy: An evaluation. Journal of Consulting Psychology, 16 , 319–324.

Posternak, M. A., & Miller, I. (2001). Untreated short-term course of major depression: A meta-analysis of studies using outcomes from studies using wait-list control groups. Journal of Affective Disorders, 66 , 139–146.

Smith, M. L., Glass, G. V., & Miller, T. I. (1980). The benefits of psychotherapy . Baltimore, MD: Johns Hopkins University Press.

Research Methods in Psychology Copyright © 2016 by University of Minnesota is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License , except where otherwise noted.

Quasi-Experimental Design: Definition, Types, Examples

Appinio Research · 19.12.2023 · 37min read

Quasi-Experimental Design Definition Types Examples

Ever wondered how researchers uncover cause-and-effect relationships in the real world, where controlled experiments are often elusive? Quasi-experimental design holds the key. In this guide, we'll unravel the intricacies of quasi-experimental design, shedding light on its definition, purpose, and applications across various domains. Whether you're a student, a professional, or simply curious about the methods behind meaningful research, join us as we delve into the world of quasi-experimental design, making complex concepts sound simple and embarking on a journey of knowledge and discovery.

What is Quasi-Experimental Design?

Quasi-experimental design is a research methodology used to study the effects of independent variables on dependent variables when full experimental control is not possible or ethical. It falls between controlled experiments, where variables are tightly controlled, and purely observational studies, where researchers have little control over variables. Quasi-experimental design mimics some aspects of experimental research but lacks randomization.

The primary purpose of quasi-experimental design is to investigate cause-and-effect relationships between variables in real-world settings. Researchers use this approach to answer research questions, test hypotheses, and explore the impact of interventions or treatments when they cannot employ traditional experimental methods. Quasi-experimental studies aim to maximize internal validity and make meaningful inferences while acknowledging practical constraints and ethical considerations.

Quasi-Experimental vs. Experimental Design

It's essential to understand the distinctions between Quasi-Experimental and Experimental Design to appreciate the unique characteristics of each approach:

  • Randomization:  In Experimental Design, random assignment of participants to groups is a defining feature. Quasi-experimental design, on the other hand, lacks randomization due to practical constraints or ethical considerations.
  • Control Groups :  Experimental Design typically includes control groups that are subjected to no treatment or a placebo. The quasi-experimental design may have comparison groups but lacks the same level of control.
  • Manipulation of IV:  Experimental Design involves the intentional manipulation of the independent variable. Quasi-experimental design often deals with naturally occurring independent variables.
  • Causal Inference:  Experimental Design allows for stronger causal inferences due to randomization and control. Quasi-experimental design permits causal inferences but with some limitations.

When to Use Quasi-Experimental Design?

A quasi-experimental design is particularly valuable in several situations:

  • Ethical Constraints:  When manipulating the independent variable is ethically unacceptable or impractical, quasi-experimental design offers an alternative to studying naturally occurring variables.
  • Real-World Settings:  When researchers want to study phenomena in real-world contexts, quasi-experimental design allows them to do so without artificial laboratory settings.
  • Limited Resources:  In cases where resources are limited and conducting a controlled experiment is cost-prohibitive, quasi-experimental design can provide valuable insights.
  • Policy and Program Evaluation:  Quasi-experimental design is commonly used in evaluating the effectiveness of policies, interventions, or programs that cannot be randomly assigned to participants.

Importance of Quasi-Experimental Design in Research

Quasi-experimental design plays a vital role in research for several reasons:

  • Addressing Real-World Complexities:  It allows researchers to tackle complex real-world issues where controlled experiments are not feasible. This bridges the gap between controlled experiments and purely observational studies.
  • Ethical Research:  It provides an honest approach when manipulating variables or assigning treatments could harm participants or violate ethical standards.
  • Policy and Practice Implications:  Quasi-experimental studies generate findings with direct applications in policy-making and practical solutions in fields such as education, healthcare, and social sciences.
  • Enhanced External Validity:  Findings from Quasi-Experimental research often have high external validity, making them more applicable to broader populations and contexts.

By embracing the challenges and opportunities of quasi-experimental design, researchers can contribute valuable insights to their respective fields and drive positive changes in the real world.

Key Concepts in Quasi-Experimental Design

In quasi-experimental design, it's essential to grasp the fundamental concepts underpinning this research methodology. Let's explore these key concepts in detail.

Independent Variable

The independent variable (IV) is the factor you aim to study or manipulate in your research. Unlike controlled experiments, where you can directly manipulate the IV, quasi-experimental design often deals with naturally occurring variables. For example, if you're investigating the impact of a new teaching method on student performance, the teaching method is your independent variable.

Dependent Variable

The dependent variable (DV) is the outcome or response you measure to assess the effects of changes in the independent variable. Continuing with the teaching method example, the dependent variable would be the students' academic performance, typically measured using test scores, grades, or other relevant metrics.

Control Groups vs. Comparison Groups

While quasi-experimental design lacks the luxury of randomly assigning participants to control and experimental groups, you can still establish comparison groups to make meaningful inferences. Control groups consist of individuals who do not receive the treatment, while comparison groups are exposed to different levels or variations of the treatment. These groups help researchers gauge the effect of the independent variable.

Pre-Test and Post-Test Measures

In quasi-experimental design, it's common practice to collect data both before and after implementing the independent variable. The initial data (pre-test) serves as a baseline, allowing you to measure changes over time (post-test). This approach helps assess the impact of the independent variable more accurately. For instance, if you're studying the effectiveness of a new drug, you'd measure patients' health before administering the drug (pre-test) and afterward (post-test).

Threats to Internal Validity

Internal validity is crucial for establishing a cause-and-effect relationship between the independent and dependent variables. However, in a quasi-experimental design, several threats can compromise internal validity. These threats include:

  • Selection Bias :  When non-randomized groups differ systematically in ways that affect the study's outcome.
  • History Effects:  External events or changes over time that influence the results.
  • Maturation Effects:  Natural changes or developments that occur within participants during the study.
  • Regression to the Mean:  The tendency for extreme scores on a variable to move closer to the mean upon retesting.
  • Attrition and Mortality:  The loss of participants over time, potentially skewing the results.
  • Testing Effects:  The mere act of testing or assessing participants can impact their subsequent performance.

Understanding these threats is essential for designing and conducting Quasi-Experimental studies that yield valid and reliable results.

Randomization and Non-Randomization

In traditional experimental designs, randomization is a powerful tool for ensuring that groups are equivalent at the outset of a study. However, quasi-experimental design often involves non-randomization due to the nature of the research. This means that participants are not randomly assigned to treatment and control groups. Instead, researchers must employ various techniques to minimize biases and ensure that the groups are as similar as possible.

For example, if you are conducting a study on the effects of a new teaching method in a real classroom setting, you cannot randomly assign students to the treatment and control groups. Instead, you might use statistical methods to match students based on relevant characteristics such as prior academic performance or socioeconomic status. This matching process helps control for potential confounding variables, increasing the validity of your study.

Types of Quasi-Experimental Designs

In quasi-experimental design, researchers employ various approaches to investigate causal relationships and study the effects of independent variables when complete experimental control is challenging. Let's explore these types of quasi-experimental designs.

One-Group Posttest-Only Design

The One-Group Posttest-Only Design is one of the simplest forms of quasi-experimental design. In this design, a single group is exposed to the independent variable, and data is collected only after the intervention has taken place. Unlike controlled experiments, there is no comparison group. This design is useful when researchers cannot administer a pre-test or when it is logistically difficult to do so.

Example : Suppose you want to assess the effectiveness of a new time management seminar. You offer the seminar to a group of employees and measure their productivity levels immediately afterward to determine if there's an observable impact.

One-Group Pretest-Posttest Design

Similar to the One-Group Posttest-Only Design, this approach includes a pre-test measure in addition to the post-test. Researchers collect data both before and after the intervention. By comparing the pre-test and post-test results within the same group, you can gain a better understanding of the changes that occur due to the independent variable.

Example : If you're studying the impact of a stress management program on participants' stress levels, you would measure their stress levels before the program (pre-test) and after completing the program (post-test) to assess any changes.

Non-Equivalent Groups Design

The Non-Equivalent Groups Design involves multiple groups, but they are not randomly assigned. Instead, researchers must carefully match or control for relevant variables to minimize biases. This design is particularly useful when random assignment is not possible or ethical.

Example : Imagine you're examining the effectiveness of two teaching methods in two different schools. You can't randomly assign students to the schools, but you can carefully match them based on factors like age, prior academic performance, and socioeconomic status to create equivalent groups.

Time Series Design

Time Series Design is an approach where data is collected at multiple time points before and after the intervention. This design allows researchers to analyze trends and patterns over time, providing valuable insights into the sustained effects of the independent variable.

Example : If you're studying the impact of a new marketing campaign on product sales, you would collect sales data at regular intervals (e.g., monthly) before and after the campaign's launch to observe any long-term trends.

Regression Discontinuity Design

Regression Discontinuity Design is employed when participants are assigned to different groups based on a specific cutoff score or threshold. This design is often used in educational and policy research to assess the effects of interventions near a cutoff point.

Example : Suppose you're evaluating the impact of a scholarship program on students' academic performance. Students who score just above or below a certain GPA threshold are assigned differently to the program. This design helps assess the program's effectiveness at the cutoff point.

Propensity Score Matching

Propensity Score Matching is a technique used to create comparable treatment and control groups in non-randomized studies. Researchers calculate propensity scores based on participants' characteristics and match individuals in the treatment group to those in the control group with similar scores.

Example : If you're studying the effects of a new medication on patient outcomes, you would use propensity scores to match patients who received the medication with those who did not but have similar health profiles.

Interrupted Time Series Design

The Interrupted Time Series Design involves collecting data at multiple time points before and after the introduction of an intervention. However, in this design, the intervention occurs at a specific point in time, allowing researchers to assess its immediate impact.

Example : Let's say you're analyzing the effects of a new traffic management system on traffic accidents. You collect accident data before and after the system's implementation to observe any abrupt changes right after its introduction.

Each of these quasi-experimental designs offers unique advantages and is best suited to specific research questions and scenarios. Choosing the right design is crucial for conducting robust and informative studies.

Advantages and Disadvantages of Quasi-Experimental Design

Quasi-experimental design offers a valuable research approach, but like any methodology, it comes with its own set of advantages and disadvantages. Let's explore these in detail.

Quasi-Experimental Design Advantages

Quasi-experimental design presents several advantages that make it a valuable tool in research:

  • Real-World Applicability:  Quasi-experimental studies often take place in real-world settings, making the findings more applicable to practical situations. Researchers can examine the effects of interventions or variables in the context where they naturally occur.
  • Ethical Considerations:  In situations where manipulating the independent variable in a controlled experiment would be unethical, quasi-experimental design provides an ethical alternative. For example, it would be unethical to assign participants to smoke for a study on the health effects of smoking, but you can study naturally occurring groups of smokers and non-smokers.
  • Cost-Efficiency:  Conducting Quasi-Experimental research is often more cost-effective than conducting controlled experiments. The absence of controlled environments and extensive manipulations can save both time and resources.

These advantages make quasi-experimental design an attractive choice for researchers facing practical or ethical constraints in their studies.

Quasi-Experimental Design Disadvantages

However, quasi-experimental design also comes with its share of challenges and disadvantages:

  • Limited Control:  Unlike controlled experiments, where researchers have full control over variables, quasi-experimental design lacks the same level of control. This limited control can result in confounding variables that make it difficult to establish causality.
  • Threats to Internal Validity:  Various threats to internal validity, such as selection bias, history effects, and maturation effects, can compromise the accuracy of causal inferences. Researchers must carefully address these threats to ensure the validity of their findings.
  • Causality Inference Challenges:  Establishing causality can be challenging in quasi-experimental design due to the absence of randomization and control. While you can make strong arguments for causality, it may not be as conclusive as in controlled experiments.
  • Potential Confounding Variables:  In a quasi-experimental design, it's often challenging to control for all possible confounding variables that may affect the dependent variable. This can lead to uncertainty in attributing changes solely to the independent variable.

Despite these disadvantages, quasi-experimental design remains a valuable research tool when used judiciously and with a keen awareness of its limitations. Researchers should carefully consider their research questions and the practical constraints they face before choosing this approach.

How to Conduct a Quasi-Experimental Study?

Conducting a Quasi-Experimental study requires careful planning and execution to ensure the validity of your research. Let's dive into the essential steps you need to follow when conducting such a study.

1. Define Research Questions and Objectives

The first step in any research endeavor is clearly defining your research questions and objectives. This involves identifying the independent variable (IV) and the dependent variable (DV) you want to study. What is the specific relationship you want to explore, and what do you aim to achieve with your research?

  • Specify Your Research Questions :  Start by formulating precise research questions that your study aims to answer. These questions should be clear, focused, and relevant to your field of study.
  • Identify the Independent Variable:  Define the variable you intend to manipulate or study in your research. Understand its significance in your study's context.
  • Determine the Dependent Variable:  Identify the outcome or response variable that will be affected by changes in the independent variable.
  • Establish Hypotheses (If Applicable):  If you have specific hypotheses about the relationship between the IV and DV, state them clearly. Hypotheses provide a framework for testing your research questions.

2. Select the Appropriate Quasi-Experimental Design

Choosing the right quasi-experimental design is crucial for achieving your research objectives. Select a design that aligns with your research questions and the available data. Consider factors such as the feasibility of implementing the design and the ethical considerations involved.

  • Evaluate Your Research Goals:  Assess your research questions and objectives to determine which type of quasi-experimental design is most suitable. Each design has its strengths and limitations, so choose one that aligns with your goals.
  • Consider Ethical Constraints:  Take into account any ethical concerns related to your research. Depending on your study's context, some designs may be more ethically sound than others.
  • Assess Data Availability:  Ensure you have access to the necessary data for your chosen design. Some designs may require extensive historical data, while others may rely on data collected during the study.

3. Identify and Recruit Participants

Selecting the right participants is a critical aspect of Quasi-Experimental research. The participants should represent the population you want to make inferences about, and you must address ethical considerations, including informed consent.

  • Define Your Target Population:  Determine the population that your study aims to generalize to. Your sample should be representative of this population.
  • Recruitment Process:  Develop a plan for recruiting participants. Depending on your design, you may need to reach out to specific groups or institutions.
  • Informed Consent:  Ensure that you obtain informed consent from participants. Clearly explain the nature of the study, potential risks, and their rights as participants.

4. Collect Data

Data collection is a crucial step in Quasi-Experimental research. You must adhere to a consistent and systematic process to gather relevant information before and after the intervention or treatment.

  • Pre-Test Measures:  If applicable, collect data before introducing the independent variable. Ensure that the pre-test measures are standardized and reliable.
  • Post-Test Measures:  After the intervention, collect post-test data using the same measures as the pre-test. This allows you to assess changes over time.
  • Maintain Data Consistency:  Ensure that data collection procedures are consistent across all participants and time points to minimize biases.

5. Analyze Data

Once you've collected your data, it's time to analyze it using appropriate statistical techniques . The choice of analysis depends on your research questions and the type of data you've gathered.

  • Statistical Analysis :  Use statistical software to analyze your data. Common techniques include t-tests , analysis of variance (ANOVA) , regression analysis , and more, depending on the design and variables.
  • Control for Confounding Variables:  Be aware of potential confounding variables and include them in your analysis as covariates to ensure accurate results.

Chi-Square Calculator :

t-Test Calculator :

6. Interpret Results

With the analysis complete, you can interpret the results to draw meaningful conclusions about the relationship between the independent and dependent variables.

  • Examine Effect Sizes:  Assess the magnitude of the observed effects to determine their practical significance.
  • Consider Significance Levels:  Determine whether the observed results are statistically significant . Understand the p-values and their implications.
  • Compare Findings to Hypotheses:  Evaluate whether your findings support or reject your hypotheses and research questions.

7. Draw Conclusions

Based on your analysis and interpretation of the results, draw conclusions about the research questions and objectives you set out to address.

  • Causal Inferences:  Discuss the extent to which your study allows for causal inferences. Be transparent about the limitations and potential alternative explanations for your findings.
  • Implications and Applications:  Consider the practical implications of your research. How do your findings contribute to existing knowledge, and how can they be applied in real-world contexts?
  • Future Research:  Identify areas for future research and potential improvements in study design. Highlight any limitations or constraints that may have affected your study's outcomes.

By following these steps meticulously, you can conduct a rigorous and informative Quasi-Experimental study that advances knowledge in your field of research.

Quasi-Experimental Design Examples

Quasi-experimental design finds applications in a wide range of research domains, including business-related and market research scenarios. Below, we delve into some detailed examples of how this research methodology is employed in practice:

Example 1: Assessing the Impact of a New Marketing Strategy

Suppose a company wants to evaluate the effectiveness of a new marketing strategy aimed at boosting sales. Conducting a controlled experiment may not be feasible due to the company's existing customer base and the challenge of randomly assigning customers to different marketing approaches. In this scenario, a quasi-experimental design can be employed.

  • Independent Variable:  The new marketing strategy.
  • Dependent Variable:  Sales revenue.
  • Design:  The company could implement the new strategy for one group of customers while maintaining the existing strategy for another group. Both groups are selected based on similar demographics and purchase history , reducing selection bias. Pre-implementation data (sales records) can serve as the baseline, and post-implementation data can be collected to assess the strategy's impact.

Example 2: Evaluating the Effectiveness of Employee Training Programs

In the context of human resources and employee development, organizations often seek to evaluate the impact of training programs. A randomized controlled trial (RCT) with random assignment may not be practical or ethical, as some employees may need specific training more than others. Instead, a quasi-experimental design can be employed.

  • Independent Variable:  Employee training programs.
  • Dependent Variable:  Employee performance metrics, such as productivity or quality of work.
  • Design:  The organization can offer training programs to employees who express interest or demonstrate specific needs, creating a self-selected treatment group. A comparable control group can consist of employees with similar job roles and qualifications who did not receive the training. Pre-training performance metrics can serve as the baseline, and post-training data can be collected to assess the impact of the training programs.

Example 3: Analyzing the Effects of a Tax Policy Change

In economics and public policy, researchers often examine the effects of tax policy changes on economic behavior. Conducting a controlled experiment in such cases is practically impossible. Therefore, a quasi-experimental design is commonly employed.

  • Independent Variable:  Tax policy changes (e.g., tax rate adjustments).
  • Dependent Variable:  Economic indicators, such as consumer spending or business investments.
  • Design:  Researchers can analyze data from different regions or jurisdictions where tax policy changes have been implemented. One region could represent the treatment group (with tax policy changes), while a similar region with no tax policy changes serves as the control group. By comparing economic data before and after the policy change in both groups, researchers can assess the impact of the tax policy changes.

These examples illustrate how quasi-experimental design can be applied in various research contexts, providing valuable insights into the effects of independent variables in real-world scenarios where controlled experiments are not feasible or ethical. By carefully selecting comparison groups and controlling for potential biases, researchers can draw meaningful conclusions and inform decision-making processes.

How to Publish Quasi-Experimental Research?

Publishing your Quasi-Experimental research findings is a crucial step in contributing to the academic community's knowledge. We'll explore the essential aspects of reporting and publishing your Quasi-Experimental research effectively.

Structuring Your Research Paper

When preparing your research paper, it's essential to adhere to a well-structured format to ensure clarity and comprehensibility. Here are key elements to include:

Title and Abstract

  • Title:  Craft a concise and informative title that reflects the essence of your study. It should capture the main research question or hypothesis.
  • Abstract:  Summarize your research in a structured abstract, including the purpose, methods, results, and conclusions. Ensure it provides a clear overview of your study.

Introduction

  • Background and Rationale:  Provide context for your study by discussing the research gap or problem your study addresses. Explain why your research is relevant and essential.
  • Research Questions or Hypotheses:  Clearly state your research questions or hypotheses and their significance.

Literature Review

  • Review of Related Work:  Discuss relevant literature that supports your research. Highlight studies with similar methodologies or findings and explain how your research fits within this context.
  • Participants:  Describe your study's participants, including their characteristics and how you recruited them.
  • Quasi-Experimental Design:  Explain your chosen design in detail, including the independent and dependent variables, procedures, and any control measures taken.
  • Data Collection:  Detail the data collection methods , instruments used, and any pre-test or post-test measures.
  • Data Analysis:  Describe the statistical techniques employed, including any control for confounding variables.
  • Presentation of Findings:  Present your results clearly, using tables, graphs, and descriptive statistics where appropriate. Include p-values and effect sizes, if applicable.
  • Interpretation of Results:  Discuss the implications of your findings and how they relate to your research questions or hypotheses.
  • Interpretation and Implications:  Analyze your results in the context of existing literature and theories. Discuss the practical implications of your findings.
  • Limitations:  Address the limitations of your study, including potential biases or threats to internal validity.
  • Future Research:  Suggest areas for future research and how your study contributes to the field.

Ethical Considerations in Reporting

Ethical reporting is paramount in Quasi-Experimental research. Ensure that you adhere to ethical standards, including:

  • Informed Consent:  Clearly state that informed consent was obtained from all participants, and describe the informed consent process.
  • Protection of Participants:  Explain how you protected the rights and well-being of your participants throughout the study.
  • Confidentiality:  Detail how you maintained privacy and anonymity, especially when presenting individual data.
  • Disclosure of Conflicts of Interest:  Declare any potential conflicts of interest that could influence the interpretation of your findings.

Common Pitfalls to Avoid

When reporting your Quasi-Experimental research, watch out for common pitfalls that can diminish the quality and impact of your work:

  • Overgeneralization:  Be cautious not to overgeneralize your findings. Clearly state the limits of your study and the populations to which your results can be applied.
  • Misinterpretation of Causality:  Clearly articulate the limitations in inferring causality in Quasi-Experimental research. Avoid making strong causal claims unless supported by solid evidence.
  • Ignoring Ethical Concerns:  Ethical considerations are paramount. Failing to report on informed consent, ethical oversight, and participant protection can undermine the credibility of your study.

Guidelines for Transparent Reporting

To enhance the transparency and reproducibility of your Quasi-Experimental research, consider adhering to established reporting guidelines, such as:

  • CONSORT Statement:  If your study involves interventions or treatments, follow the CONSORT guidelines for transparent reporting of randomized controlled trials.
  • STROBE Statement:  For observational studies, the STROBE statement provides guidance on reporting essential elements.
  • PRISMA Statement:  If your research involves systematic reviews or meta-analyses, adhere to the PRISMA guidelines.
  • Transparent Reporting of Evaluations with Non-Randomized Designs (TREND):  TREND guidelines offer specific recommendations for transparently reporting non-randomized designs, including Quasi-Experimental research.

By following these reporting guidelines and maintaining the highest ethical standards, you can contribute to the advancement of knowledge in your field and ensure the credibility and impact of your Quasi-Experimental research findings.

Quasi-Experimental Design Challenges

Conducting a Quasi-Experimental study can be fraught with challenges that may impact the validity and reliability of your findings. We'll take a look at some common challenges and provide strategies on how you can address them effectively.

Selection Bias

Challenge:  Selection bias occurs when non-randomized groups differ systematically in ways that affect the study's outcome. This bias can undermine the validity of your research, as it implies that the groups are not equivalent at the outset of the study.

Addressing Selection Bias:

  • Matching:  Employ matching techniques to create comparable treatment and control groups. Match participants based on relevant characteristics, such as age, gender, or prior performance, to balance the groups.
  • Statistical Controls:  Use statistical controls to account for differences between groups. Include covariates in your analysis to adjust for potential biases.
  • Sensitivity Analysis:  Conduct sensitivity analyses to assess how vulnerable your results are to selection bias. Explore different scenarios to understand the impact of potential bias on your conclusions.

History Effects

Challenge:  History effects refer to external events or changes over time that influence the study's results. These external factors can confound your research by introducing variables you did not account for.

Addressing History Effects:

  • Collect Historical Data:  Gather extensive historical data to understand trends and patterns that might affect your study. By having a comprehensive historical context, you can better identify and account for historical effects.
  • Control Groups:  Include control groups whenever possible. By comparing the treatment group's results to those of a control group, you can account for external influences that affect both groups equally.
  • Time Series Analysis :  If applicable, use time series analysis to detect and account for temporal trends. This method helps differentiate between the effects of the independent variable and external events.

Maturation Effects

Challenge:  Maturation effects occur when participants naturally change or develop throughout the study, independent of the intervention. These changes can confound your results, making it challenging to attribute observed effects solely to the independent variable.

Addressing Maturation Effects:

  • Randomization:  If possible, use randomization to distribute maturation effects evenly across treatment and control groups. Random assignment minimizes the impact of maturation as a confounding variable.
  • Matched Pairs:  If randomization is not feasible, employ matched pairs or statistical controls to ensure that both groups experience similar maturation effects.
  • Shorter Time Frames:  Limit the duration of your study to reduce the likelihood of significant maturation effects. Shorter studies are less susceptible to long-term maturation.

Regression to the Mean

Challenge:  Regression to the mean is the tendency for extreme scores on a variable to move closer to the mean upon retesting. This can create the illusion of an intervention's effectiveness when, in reality, it's a natural statistical phenomenon.

Addressing Regression to the Mean:

  • Use Control Groups:  Include control groups in your study to provide a baseline for comparison. This helps differentiate genuine intervention effects from regression to the mean.
  • Multiple Data Points:  Collect numerous data points to identify patterns and trends. If extreme scores regress to the mean in subsequent measurements, it may be indicative of regression to the mean rather than a true intervention effect.
  • Statistical Analysis:  Employ statistical techniques that account for regression to the mean when analyzing your data. Techniques like analysis of covariance (ANCOVA) can help control for baseline differences.

Attrition and Mortality

Challenge:  Attrition refers to the loss of participants over the course of your study, while mortality is the permanent loss of participants. High attrition rates can introduce biases and affect the representativeness of your sample.

Addressing Attrition and Mortality:

  • Careful Participant Selection:  Select participants who are likely to remain engaged throughout the study. Consider factors that may lead to attrition, such as participant motivation and commitment.
  • Incentives:  Provide incentives or compensation to participants to encourage their continued participation.
  • Follow-Up Strategies:  Implement effective follow-up strategies to reduce attrition. Regular communication and reminders can help keep participants engaged.
  • Sensitivity Analysis:  Conduct sensitivity analyses to assess the impact of attrition and mortality on your results. Compare the characteristics of participants who dropped out with those who completed the study.

Testing Effects

Challenge:  Testing effects occur when the mere act of testing or assessing participants affects their subsequent performance. This phenomenon can lead to changes in the dependent variable that are unrelated to the independent variable.

Addressing Testing Effects:

  • Counterbalance Testing:  If possible, counterbalance the order of tests or assessments between treatment and control groups. This helps distribute the testing effects evenly across groups.
  • Control Groups:  Include control groups subjected to the same testing or assessment procedures as the treatment group. By comparing the two groups, you can determine whether testing effects have influenced the results.
  • Minimize Testing Frequency:  Limit the frequency of testing or assessments to reduce the likelihood of testing effects. Conducting fewer assessments can mitigate the impact of repeated testing on participants.

By proactively addressing these common challenges, you can enhance the validity and reliability of your Quasi-Experimental study, making your findings more robust and trustworthy.

Conclusion for Quasi-Expermental Design

Quasi-experimental design is a powerful tool that helps researchers investigate cause-and-effect relationships in real-world situations where strict control is not always possible. By understanding the key concepts, types of designs, and how to address challenges, you can conduct robust research and contribute valuable insights to your field. Remember, quasi-experimental design bridges the gap between controlled experiments and purely observational studies, making it an essential approach in various fields, from business and market research to public policy and beyond. So, whether you're a researcher, student, or decision-maker, the knowledge of quasi-experimental design empowers you to make informed choices and drive positive changes in the world.

How to Supercharge Quasi-Experimental Design with Real-Time Insights?

Introducing Appinio , the real-time market research platform that transforms the world of quasi-experimental design. Imagine having the power to conduct your own market research in minutes, obtaining actionable insights that fuel your data-driven decisions. Appinio takes care of the research and tech complexities, freeing you to focus on what truly matters for your business.

Here's why Appinio stands out:

  • Lightning-Fast Insights:  From formulating questions to uncovering insights, Appinio delivers results in minutes, ensuring you get the answers you need when you need them.
  • No Research Degree Required:  Our intuitive platform is designed for everyone, eliminating the need for a PhD in research. Anyone can dive in and start harnessing the power of real-time consumer insights.
  • Global Reach, Local Expertise:  With access to over 90 countries and the ability to define precise target groups based on 1200+ characteristics, you can conduct Quasi-Experimental research on a global scale while maintaining a local touch.

Register now EN

Get free access to the platform!

Get facts and figures 🧠

Want to see more data insights? Our free reports are just the right thing for you!

Wait, there's more

Trustly uses Appinio’s insights to revolutionize utility bill payments

04.11.2024 | 5min read

Trustly uses Appinio’s insights to revolutionize utility bill payments

Track Your Customer Retention & Brand Metrics for Post-Holiday Success

19.09.2024 | 9min read

Track Your Customer Retention & Brand Metrics for Post-Holiday Success

Creative Checkup – Optimize Advertising Slogans & Creatives for maximum ROI

16.09.2024 | 10min read

Creative Checkup – Optimize Advertising Slogans & Creatives for ROI

Child Care and Early Education Research Connections

Experiments and quasi-experiments.

This page includes an explanation of the types, key components, validity, ethics, and advantages and disadvantages of experimental design.

An experiment is a study in which the researcher manipulates the level of some independent variable and then measures the outcome. Experiments are powerful techniques for evaluating cause-and-effect relationships. Many researchers consider experiments the "gold standard" against which all other research designs should be judged. Experiments are conducted both in the laboratory and in real life situations.

Types of Experimental Design

There are two basic types of research design:

  • True experiments
  • Quasi-experiments

The purpose of both is to examine the cause of certain phenomena.

True experiments, in which all the important factors that might affect the phenomena of interest are completely controlled, are the preferred design. Often, however, it is not possible or practical to control all the key factors, so it becomes necessary to implement a quasi-experimental research design.

Similarities between true and quasi-experiments:

  • Study participants are subjected to some type of treatment or condition
  • Some outcome of interest is measured
  • The researchers test whether differences in this outcome are related to the treatment

Differences between true experiments and quasi-experiments:

  • In a true experiment, participants are randomly assigned to either the treatment or the control group, whereas they are not assigned randomly in a quasi-experiment
  • In a quasi-experiment, the control and treatment groups differ not only in terms of the experimental treatment they receive, but also in other, often unknown or unknowable, ways. Thus, the researcher must try to statistically control for as many of these differences as possible
  • Because control is lacking in quasi-experiments, there may be several "rival hypotheses" competing with the experimental manipulation as explanations for observed results

Key Components of Experimental Research Design

The manipulation of predictor variables.

In an experiment, the researcher manipulates the factor that is hypothesized to affect the outcome of interest. The factor that is being manipulated is typically referred to as the treatment or intervention. The researcher may manipulate whether research subjects receive a treatment (e.g., antidepressant medicine: yes or no) and the level of treatment (e.g., 50 mg, 75 mg, 100 mg, and 125 mg).

Suppose, for example, a group of researchers was interested in the causes of maternal employment. They might hypothesize that the provision of government-subsidized child care would promote such employment. They could then design an experiment in which some subjects would be provided the option of government-funded child care subsidies and others would not. The researchers might also manipulate the value of the child care subsidies in order to determine if higher subsidy values might result in different levels of maternal employment.

Random Assignment

  • Study participants are randomly assigned to different treatment groups
  • All participants have the same chance of being in a given condition
  • Participants are assigned to either the group that receives the treatment, known as the "experimental group" or "treatment group," or to the group which does not receive the treatment, referred to as the "control group"
  • Random assignment neutralizes factors other than the independent and dependent variables, making it possible to directly infer cause and effect

Random Sampling

Traditionally, experimental researchers have used convenience sampling to select study participants. However, as research methods have become more rigorous, and the problems with generalizing from a convenience sample to the larger population have become more apparent, experimental researchers are increasingly turning to random sampling. In experimental policy research studies, participants are often randomly selected from program administrative databases and randomly assigned to the control or treatment groups.

Validity of Results

The two types of validity of experiments are internal and external. It is often difficult to achieve both in social science research experiments.

Internal Validity

  • When an experiment is internally valid, we are certain that the independent variable (e.g., child care subsidies) caused the outcome of the study (e.g., maternal employment)
  • When subjects are randomly assigned to treatment or control groups, we can assume that the independent variable caused the observed outcomes because the two groups should not have differed from one another at the start of the experiment
  • For example, take the child care subsidy example above. Since research subjects were randomly assigned to the treatment (child care subsidies available) and control (no child care subsidies available) groups, the two groups should not have differed at the outset of the study. If, after the intervention, mothers in the treatment group were more likely to be working, we can assume that the availability of child care subsidies promoted maternal employment

One potential threat to internal validity in experiments occurs when participants either drop out of the study or refuse to participate in the study. If particular types of individuals drop out or refuse to participate more often than individuals with other characteristics, this is called differential attrition. For example, suppose an experiment was conducted to assess the effects of a new reading curriculum. If the new curriculum was so tough that many of the slowest readers dropped out of school, the school with the new curriculum would experience an increase in the average reading scores. The reason they experienced an increase in reading scores, however, is because the worst readers left the school, not because the new curriculum improved students' reading skills.

External Validity

  • External validity is also of particular concern in social science experiments
  • It can be very difficult to generalize experimental results to groups that were not included in the study
  • Studies that randomly select participants from the most diverse and representative populations are more likely to have external validity
  • The use of random sampling techniques makes it easier to generalize the results of studies to other groups

For example, a research study shows that a new curriculum improved reading comprehension of third-grade children in Iowa. To assess the study's external validity, you would ask whether this new curriculum would also be effective with third graders in New York or with children in other elementary grades.

Glossary terms related to validity:

  • internal validity
  • external validity
  • differential attrition

It is particularly important in experimental research to follow ethical guidelines. Protecting the health and safety of research subjects is imperative. In order to assure subject safety, all researchers should have their project reviewed by the Institutional Review Boards (IRBS). The  National Institutes of Health  supplies strict guidelines for project approval. Many of these guidelines are based on the  Belmont Report  (pdf).

The basic ethical principles:

  • Respect for persons  -- requires that research subjects are not coerced into participating in a study and requires the protection of research subjects who have diminished autonomy
  • Beneficence  -- requires that experiments do not harm research subjects, and that researchers minimize the risks for subjects while maximizing the benefits for them
  • Justice  -- requires that all forms of differential treatment among research subjects be justified

Advantages and Disadvantages of Experimental Design

The environment in which the research takes place can often be carefully controlled. Consequently, it is easier to estimate the true effect of the variable of interest on the outcome of interest.

Disadvantages

It is often difficult to assure the external validity of the experiment, due to the frequently nonrandom selection processes and the artificial nature of the experimental context.

The use and interpretation of quasi-experimental design

Last updated

6 February 2023

Reviewed by

Miroslav Damyanov

Short on time? Get an AI generated summary of this article instead

  • What is a quasi-experimental design?

Commonly used in medical informatics (a field that uses digital information to ensure better patient care), researchers generally use this design to evaluate the effectiveness of a treatment – perhaps a type of antibiotic or psychotherapy, or an educational or policy intervention.

Even though quasi-experimental design has been used for some time, relatively little is known about it. Read on to learn the ins and outs of this research design.

Make research less tedious

Dovetail streamlines research to help you uncover and share actionable insights

  • When to use a quasi-experimental design

A quasi-experimental design is used when it's not logistically feasible or ethical to conduct randomized, controlled trials. As its name suggests, a quasi-experimental design is almost a true experiment. However, researchers don't randomly select elements or participants in this type of research.

Researchers prefer to apply quasi-experimental design when there are ethical or practical concerns. Let's look at these two reasons more closely.

Ethical reasons

In some situations, the use of randomly assigned elements can be unethical. For instance, providing public healthcare to one group and withholding it to another in research is unethical. A quasi-experimental design would examine the relationship between these two groups to avoid physical danger.

Practical reasons

Randomized controlled trials may not be the best approach in research. For instance, it's impractical to trawl through large sample sizes of participants without using a particular attribute to guide your data collection .

Recruiting participants and properly designing a data-collection attribute to make the research a true experiment requires a lot of time and effort, and can be expensive if you don’t have a large funding stream.

A quasi-experimental design allows researchers to take advantage of previously collected data and use it in their study.

  • Examples of quasi-experimental designs

Quasi-experimental research design is common in medical research, but any researcher can use it for research that raises practical and ethical concerns. Here are a few examples of quasi-experimental designs used by different researchers:

Example 1: Determining the effectiveness of math apps in supplementing math classes

A school wanted to supplement its math classes with a math app. To select the best app, the school decided to conduct demo tests on two apps before selecting the one they will purchase.

Scope of the research

Since every grade had two math teachers, each teacher used one of the two apps for three months. They then gave the students the same math exams and compared the results to determine which app was most effective.

Reasons why this is a quasi-experimental study

This simple study is a quasi-experiment since the school didn't randomly assign its students to the applications. They used a pre-existing class structure to conduct the study since it was impractical to randomly assign the students to each app.

Example 2: Determining the effectiveness of teaching modern leadership techniques in start-up businesses

A hypothetical quasi-experimental study was conducted in an economically developing country in a mid-sized city.

Five start-ups in the textile industry and five in the tech industry participated in the study. The leaders attended a six-week workshop on leadership style, team management, and employee motivation.

After a year, the researchers assessed the performance of each start-up company to determine growth. The results indicated that the tech start-ups were further along in their growth than the textile companies.

The basis of quasi-experimental research is a non-randomized subject-selection process. This study didn't use specific aspects to determine which start-up companies should participate. Therefore, the results may seem straightforward, but several aspects may determine the growth of a specific company, apart from the variables used by the researchers.

Example 3: A study to determine the effects of policy reforms and of luring foreign investment on small businesses in two mid-size cities

In a study to determine the economic impact of government reforms in an economically developing country, the government decided to test whether creating reforms directed at small businesses or luring foreign investments would spur the most economic development.

The government selected two cities with similar population demographics and sizes. In one of the cities, they implemented specific policies that would directly impact small businesses, and in the other, they implemented policies to attract foreign investment.

After five years, they collected end-of-year economic growth data from both cities. They looked at elements like local GDP growth, unemployment rates, and housing sales.

The study used a non-randomized selection process to determine which city would participate in the research. Researchers left out certain variables that would play a crucial role in determining the growth of each city. They used pre-existing groups of people based on research conducted in each city, rather than random groups.

  • Advantages of a quasi-experimental design

Some advantages of quasi-experimental designs are:

Researchers can manipulate variables to help them meet their study objectives.

It offers high external validity, making it suitable for real-world applications, specifically in social science experiments.

Integrating this methodology into other research designs is easier, especially in true experimental research. This cuts down on the time needed to determine your outcomes.

  • Disadvantages of a quasi-experimental design

Despite the pros that come with a quasi-experimental design, there are several disadvantages associated with it, including the following:

It has a lower internal validity since researchers do not have full control over the comparison and intervention groups or between time periods because of differences in characteristics in people, places, or time involved. It may be challenging to determine whether all variables have been used or whether those used in the research impacted the results.

There is the risk of inaccurate data since the research design borrows information from other studies.

There is the possibility of bias since researchers select baseline elements and eligibility.

  • What are the different quasi-experimental study designs?

There are three distinct types of quasi-experimental designs:

Nonequivalent

Regression discontinuity, natural experiment.

This is a hybrid of experimental and quasi-experimental methods and is used to leverage the best qualities of the two. Like the true experiment design, nonequivalent group design uses pre-existing groups believed to be comparable. However, it doesn't use randomization, the lack of which is a crucial element for quasi-experimental design.

Researchers usually ensure that no confounding variables impact them throughout the grouping process. This makes the groupings more comparable.

Example of a nonequivalent group design

A small study was conducted to determine whether after-school programs result in better grades. Researchers randomly selected two groups of students: one to implement the new program, the other not to. They then compared the results of the two groups.

This type of quasi-experimental research design calculates the impact of a specific treatment or intervention. It uses a criterion known as "cutoff" that assigns treatment according to eligibility.

Researchers often assign participants above the cutoff to the treatment group. This puts a negligible distinction between the two groups (treatment group and control group).

Example of regression discontinuity

Students must achieve a minimum score to be enrolled in specific US high schools. Since the cutoff score used to determine eligibility for enrollment is arbitrary, researchers can assume that the disparity between students who only just fail to achieve the cutoff point and those who barely pass is a small margin and is due to the difference in the schools that these students attend.

Researchers can then examine the long-term effects of these two groups of kids to determine the effect of attending certain schools. This information can be applied to increase the chances of students being enrolled in these high schools.

This research design is common in laboratory and field experiments where researchers control target subjects by assigning them to different groups. Researchers randomly assign subjects to a treatment group using nature or an external event or situation.

However, even with random assignment, this research design cannot be called a true experiment since nature aspects are observational. Researchers can also exploit these aspects despite having no control over the independent variables.

Example of the natural experiment approach

An example of a natural experiment is the 2008 Oregon Health Study.

Oregon intended to allow more low-income people to participate in Medicaid.

Since they couldn't afford to cover every person who qualified for the program, the state used a random lottery to allocate program slots.

Researchers assessed the program's effectiveness by assigning the selected subjects to a randomly assigned treatment group, while those that didn't win the lottery were considered the control group.

  • Differences between quasi-experiments and true experiments

There are several differences between a quasi-experiment and a true experiment:

Participants in true experiments are randomly assigned to the treatment or control group, while participants in a quasi-experiment are not assigned randomly.

In a quasi-experimental design, the control and treatment groups differ in unknown or unknowable ways, apart from the experimental treatments that are carried out. Therefore, the researcher should try as much as possible to control these differences.

Quasi-experimental designs have several "competing hypotheses," which compete with experimental manipulation to explain the observed results.

Quasi-experiments tend to have lower internal validity (the degree of confidence in the research outcomes) than true experiments, but they may offer higher external validity (whether findings can be extended to other contexts) as they involve real-world interventions instead of controlled interventions in artificial laboratory settings.

Despite the distinct difference between true and quasi-experimental research designs, these two research methodologies share the following aspects:

Both study methods subject participants to some form of treatment or conditions.

Researchers have the freedom to measure some of the outcomes of interest.

Researchers can test whether the differences in the outcomes are associated with the treatment.

  • An example comparing a true experiment and quasi-experiment

Imagine you wanted to study the effects of junk food on obese people. Here's how you would do this as a true experiment and a quasi-experiment:

How to carry out a true experiment

In a true experiment, some participants would eat junk foods, while the rest would be in the control group, adhering to a regular diet. At the end of the study, you would record the health and discomfort of each group.

This kind of experiment would raise ethical concerns since the participants assigned to the treatment group are required to eat junk food against their will throughout the experiment. This calls for a quasi-experimental design.

How to carry out a quasi-experiment

In quasi-experimental research, you would start by finding out which participants want to try junk food and which prefer to stick to a regular diet. This allows you to assign these two groups based on subject choice.

In this case, you didn't assign participants to a particular group, so you can confidently use the results from the study.

When is a quasi-experimental design used?

Quasi-experimental designs are used when researchers don’t want to use randomization when evaluating their intervention.

What are the characteristics of quasi-experimental designs?

Some of the characteristics of a quasi-experimental design are:

Researchers don't randomly assign participants into groups, but study their existing characteristics and assign them accordingly.

Researchers study the participants in pre- and post-testing to determine the progress of the groups.

Quasi-experimental design is ethical since it doesn’t involve offering or withholding treatment at random.

Quasi-experimental design encompasses a broad range of non-randomized intervention studies. This design is employed when it is not ethical or logistically feasible to conduct randomized controlled trials. Researchers typically employ it when evaluating policy or educational interventions, or in medical or therapy scenarios.

How do you analyze data in a quasi-experimental design?

You can use two-group tests, time-series analysis, and regression analysis to analyze data in a quasi-experiment design. Each option has specific assumptions, strengths, limitations, and data requirements.

Should you be using a customer insights hub?

Do you want to discover previous research faster?

Do you share your research findings with others?

Do you analyze research data?

Start for free today, add your research, and get to key insights faster

Editor’s picks

Last updated: 5 September 2023

Last updated: 19 January 2023

Last updated: 11 September 2023

Last updated: 21 September 2023

Last updated: 21 June 2023

Last updated: 16 December 2023

Last updated: 30 September 2024

Last updated: 11 January 2024

Last updated: 14 February 2024

Last updated: 27 January 2024

Last updated: 17 January 2024

Last updated: 13 May 2024

Latest articles

Related topics, a whole new way to understand your customer is here, log in or sign up.

Get started for free

quasi experimental research design goal

  • Voxco Online
  • Voxco Panel Management
  • Voxco Panel Portal
  • Voxco Audience
  • Voxco Mobile Offline
  • Voxco Dialer Cloud
  • Voxco Dialer On-premise
  • Voxco TCPA Connect
  • Voxco Analytics
  • Voxco Text & Sentiment Analysis

quasi experimental research design goal

  • 40+ question types
  • Drag-and-drop interface
  • Skip logic and branching
  • Multi-lingual survey
  • Text piping
  • Question library
  • CSS customization
  • White-label surveys
  • Customizable ‘Thank You’ page
  • Customizable survey theme
  • Reminder send-outs
  • Survey rewards
  • Social media
  • Website surveys
  • Correlation analysis
  • Cross-tabulation analysis
  • Trend analysis
  • Real-time dashboard
  • Customizable report
  • Email address validation
  • Recaptcha validation
  • SSL security

Take a peek at our powerful survey features to design surveys that scale discoveries.

Download feature sheet.

  • Hospitality
  • Academic Research
  • Customer Experience
  • Employee Experience
  • Product Experience
  • Market Research
  • Social Research
  • Data Analysis

Explore Voxco 

Need to map Voxco’s features & offerings? We can help!

Watch a Demo 

Download Brochures 

Get a Quote

  • NPS Calculator
  • CES Calculator
  • A/B Testing Calculator
  • Margin of Error Calculator
  • Sample Size Calculator
  • CX Strategy & Management Hub
  • Market Research Hub
  • Patient Experience Hub
  • Employee Experience Hub
  • NPS Knowledge Hub
  • Market Research Guide
  • Customer Experience Guide
  • Survey Research Guides
  • Survey Template Library
  • Webinars and Events
  • Feature Sheets
  • Try a sample survey
  • Professional Services

quasi experimental research design goal

Get exclusive insights into research trends and best practices from top experts! Access Voxco’s ‘State of Research Report 2024 edition’ .

We’ve been avid users of the Voxco platform now for over 20 years. It gives us the flexibility to routinely enhance our survey toolkit and provides our clients with a more robust dataset and story to tell their clients.

VP Innovation & Strategic Partnerships, The Logit Group

  • Client Stories
  • Voxco Reviews
  • Why Voxco Research?
  • Careers at Voxco
  • Vulnerabilities and Ethical Hacking

Explore Regional Offices

  • Survey Software The world’s leading omnichannel survey software
  • Online Survey Tools Create sophisticated surveys with ease.
  • Mobile Offline Conduct efficient field surveys.
  • Text Analysis
  • Close The Loop
  • Automated Translations
  • NPS Dashboard
  • CATI Manage high volume phone surveys efficiently
  • Cloud/On-premise Dialer TCPA compliant Cloud on-premise dialer
  • IVR Survey Software Boost productivity with automated call workflows.
  • Analytics Analyze survey data with visual dashboards
  • Panel Manager Nurture a loyal community of respondents.
  • Survey Portal Best-in-class user friendly survey portal.
  • Voxco Audience Conduct targeted sample research in hours.
  • Predictive Analytics
  • Customer 360
  • Customer Loyalty
  • Fraud & Risk Management
  • AI/ML Enablement Services
  • Credit Underwriting

quasi experimental research design goal

Find the best survey software for you! (Along with a checklist to compare platforms)

Get Buyer’s Guide

  • 100+ question types
  • SMS surveys
  • Financial Services
  • Banking & Financial Services
  • Retail Solution
  • Risk Management
  • Customer Lifecycle Solutions
  • Net Promoter Score
  • Customer Behaviour Analytics
  • Customer Segmentation
  • Data Unification

Explore Voxco 

Watch a Demo 

Download Brochures 

  • CX Strategy & Management Hub
  • The Voxco Guide to Customer Experience
  • Professional services
  • Blogs & White papers
  • Case Studies

Find the best customer experience platform

Uncover customer pain points, analyze feedback and run successful CX programs with the best CX platform for your team.

Get the Guide Now

quasi experimental research design goal

VP Innovation & Strategic Partnerships, The Logit Group

  • Why Voxco Intelligence?
  • Our clients
  • Client stories
  • Featuresheets

Quasi-Experimental Design: Methods & Applications

SHARE THE ARTICLE ON

What is a Quasi-Experimental Design? Digital Customer Experience

Quasi-experimental design, a fascinating method in the realm of research, offers a unique approach to uncovering cause-and-effect relationships. Unlike traditional experiments, where researchers randomly assign participants to groups, studies work with real-world constraints, employing non-random criteria for group allocation. This flexibility makes it a practical choice for exploring complex scenarios where strict experimental controls aren’t feasible or ethical.

Unlock the potential of intuitive design, seamless project management, and unparalleled support.

Don’t miss out on this opportunity to elevate your research game

What is a Quasi-Experimental Design?

What is a Quasi-Experimental Design? Digital Customer Experience

Think of quasi-experimental design as a clever way scientists investigate cause and effect without the strict rules of a lab. Instead of assigning subjects randomly, researchers work with what they’ve got, making it more practical for real-world situations.

In experimental research, researchers divide participants into an experimental group and a control group. The experimental group receives the treatment being studied, while the control group does not. In a true experiment, researchers determine which group each participant joins through a random assignment. 

However, some studies choose a different approach called quasi-experimental research design. This design also aims to uncover cause-and-effect relationships between variables, but it assigns participants to groups using non-random criteria.

Types of Quasi-Experimental Designs

Let’s explore the most common types of designs:

Regression Discontinuity:

  • The regression discontinuity approach measures the impact of the treatment, or independent variable, by applying a treatment assignment mechanism based on a continuous eligibility index with a continuous distribution.
  • The selection process for the treatment group involves determining whether participants’ values on a predetermined numeric rating scale exceed a designated threshold. Individuals who surpass this threshold receive the treatment, while those who fall below it do not, thereby becoming part of the control group instead.

Non-Equivalent Group Design:

  • In the non-equivalent groups design, researchers choose two groups: one receives the treatment while the other does not. This method does not entail random assignment, as researchers work with pre-existing groups and do not allocate subjects to either group randomly. Although researchers strive to select two groups as similar as possible, it remains uncertain whether the groups are genuinely comparable.
  • The design earned its name, “non-equivalent groups design,” precisely because it acknowledges the probable lack of equivalence between the two groups. This recognition stems from the understanding that creating truly comparable groups through random assignment is highly unlikely.

Natural Experiments:

  • In both laboratory and field experiments, researchers typically decide how to assign subjects to groups, whether through random or non-random criteria. However, in natural experiments, a naturally occurring external event or situation causes the random assignment of subjects to different groups. Consequently, factors influencing assignment lie beyond the investigators’ control.
  • Many natural experiments utilize a method resembling random assignment, but they still don’t qualify as true experiments due to their reliance on the observational method. Researchers commonly employ natural experiments in situations such as policy changes, weather events, and natural disasters.

These quasi-experimental designs offer researchers flexible alternatives to traditional experiments, allowing exploration of cause-and-effect relationships in various contexts.

When designing a research study, consider the parallels between crafting thoughtful experiment designs and creating impactful resumes. Utilizing well-structured resume formatting templates can similarly bring clarity to your professional presentation. Just as intuitive experimental design contributes to effective research outcomes, a polished resume template ensures that one presents their qualifications compellingly.

Discover how Coyne Research boosted productivity by 100% with Voxco!

New call-to-action

Example of Quasi-Experimental Designs

Through these examples, we’ll uncover the practical applications and implications of quasi-experimental research method, Here are real-Life Example 

Before-and-After Studies:

Imagine a community health initiative introducing a new fitness program to combat obesity. Researchers assess participants’ weight and fitness levels before and after the program implementation. While participants weren’t randomly assigned, the program’s impact on health outcomes can still be evaluated.

Interrupted Time Series Analysis:

Consider a study evaluating the effect of a new traffic regulation on accident rates. Accident data is collected over several months before and after the regulation’s implementation. By analyzing trends in accident frequency, researchers can assess whether the intervention had a significant impact.

Comparison with Historical Controls:

Picture a hospital implementing a new surgical procedure for a specific medical condition. Patients undergoing the new procedure are compared with similar patients who received conventional treatment in the past. Although not randomly assigned, comparing outcomes between the two groups provides valuable insights into the procedure’s effectiveness.

These examples demonstrate how quasi-experimental designs can be applied in real-world settings to assess the impact of interventions or changes, despite the absence of randomization.

Application of the Quasi-Experimental Design

Quasi-experimental studies have lower internal validity than true experiments and also cannot establish a causal relationship between variables as effectively. So why do researchers use it? 

There are certain situations where the use of a quasi-experimental design is more suited to the study. This is especially true for studies where it would be unethical to withhold treatment from a subject on a random basis. In such situations, researchers can utilize quasi-experimental design to circumvent any ethical issues.

Additionally, another context in which a quasi-experimental design is more appropriate is when the true experiment design is not feasible. This could be due to the high expenses associated with true experiments. It could also be due to the fact that true experiments generally involve a lot of work to effectively design an experimental intervention for the threshold of subjects required to justify the research as a true experiment.

See how you can design branded surveys with smart flow using Voxco Online.

 ✔ 450+ global brands in 40+ countries 

 ✔ 100Mn+ annual surveys

Advantages of the Quasi-Experimental Design

The following are a few advantages of utilizing a quasi-experimental research design:

  • Less Expensive: One of the most prominent advantages of quasi-experimental studies is that they are less expensive and require relatively fewer resources than randomized controlled trials. 
  • Higher External Validity: Relative to true experiments, quasi-experimental studies tend to have higher external validity as they often involve real-world interventions rather than artificial laboratory settings. This makes it more likely to reflect real-world situations and settings. 

Disadvantages of the Quasi-Experimental Design

The following are a few disadvantages of utilizing a quasi-experimental research design:

  • Risk of Confounding Bias: The absence of randomization in quasi-experimental designs complicates or even renders impossible, in some cases, the elimination of confounding variables and their impact on the causal relationship under investigation.
  • Low Internal Validity: Compared to true experiments, quasi-experimental studies have lower internal validity and therefore aren’t as effective in establishing causality. 

Explore all the survey question types possible on Voxco

Differences between quasi-experiments and true experiments.

Quasi-experimental designs and true experiments are both research methods used to investigate cause-and-effect relationships. However, they differ significantly in several key aspects:

while both quasi-experimental designs and true experiments aim to uncover cause-and-effect relationships, they differ in terms of control over variables, randomization, and ethical considerations. Understanding these differences is crucial for researchers when selecting the most appropriate research method for their study.

In conclusion, quasi-experimental designs offer valuable opportunities for researchers to investigate cause-and-effect relationships in diverse fields, ranging from healthcare to social sciences. Despite their limitations, such as the risk of confounding bias and lower internal validity compared to true experiments, quasi-experimental methods provide a practical and ethical approach to studying complex phenomena. 

By leveraging innovative designs like regression discontinuity and natural experiments, researchers can navigate the complexities of real-world scenarios while generating meaningful insights. As we continue to explore the boundaries of research methodology, platforms like Voxco provide essential tools and support for conducting and analyzing, driving advancements in knowledge and understanding.

Market Research toolkit to start your market research surveys and studies.

FAQs on Quasi-Experimental Design

What is a quasi-experimental research design?

The quasi-experimental design, similar to true experiments, is a research design that aims to identify the causal relationship between an independent and dependent variable. However, unlike true experiments, quasi-experimental studies utilize non-random criteria while assigning subjects to groups.

What are the different types of quasi-experimental research designs?

Some common types of quasi-experimental designs are regression discontinuity, nonequivalent groups design, and natural experiments.

What are some of the advantages of the quasi-experimental design?

Some advantages of quasi-experimental studies are that, when compared to true experiments, they are less expensive and have higher external validity.

Explore Voxco Survey Software

+ Omnichannel Survey Software 

+ Online Survey Software 

+ CATI Survey Software 

+ IVR Survey Software 

+ Market Research Tool

+ Customer Experience Tool 

+ Product Experience Software 

+ Enterprise Survey Software 

What is a Quasi-Experimental Design? Digital Customer Experience

A Guide to Digital Customer Experience (DCX) in 2023

A Guide to Digital Customer Experience (DCX) in 2024 SHARE THE ARTICLE ON Table of Contents With technology advancing at an exponential rate, businesses that

What is a Quasi-Experimental Design? Digital Customer Experience

ROI for CX transformation

How to quantify ROI for CX Transformation? SHARE THE ARTICLE ON Table of Contents Customer experience informs how your customers perceive their interaction and journey

Improving your business’s customer focus

Improving your business’s customer focus SHARE THE ARTICLE ON Share on facebook Share on twitter Share on linkedin Table of Contents Customer focus follows an

Using a t-test

Using a t-test SHARE THE ARTICLE ON Share on facebook Share on twitter Share on linkedin Table of Contents A t-test is a statistical technique

What is Digital Customer Experience2

Digital customer experience : How to measure it ?

Digital customer experience : How to measure it ? SHARE THE ARTICLE ON Table of Contents The convenience and comfort offered by the online world

Importance of Optimising Post purchase Customer Experience cvr

70 Customer Experience Statistics you should know

70 Customer Experience Statistics you should know Customer Experience Ensuring an excellent customer experience can be tricky but an effective guide can help. Download Now

IMAGES

  1. Experimental Research Design Ppt Presentation

    quasi experimental research design goal

  2. What Is Quasi Experimental Research

    quasi experimental research design goal

  3. 5 Quasi-Experimental Design Examples (2024)

    quasi experimental research design goal

  4. The quasi-experimental research design's conceptual framework

    quasi experimental research design goal

  5. PPT

    quasi experimental research design goal

  6. Graphical representation of the Quasi-Experimental design with the

    quasi experimental research design goal

COMMENTS

  1. Quasi-Experimental Research Design

    Quasi-experimental research design is a widely used methodology in social sciences, education, healthcare, and other fields to evaluate the impact of an intervention or treatment. Unlike true experimental designs, quasi-experiments lack random assignment, which can limit control over external factors but still offer valuable insights into cause ...

  2. Quasi-Experimental Design

    True experimental design Quasi-experimental design; Assignment to treatment: The researcher randomly assigns subjects to control and treatment groups.: Some other, non-random method is used to assign subjects to groups. Control over treatment: The researcher usually designs the treatment.: The researcher often does not have control over the treatment, but instead studies pre-existing groups ...

  3. 7.3 Quasi-Experimental Research

    Learning Objectives. Explain what quasi-experimental research is and distinguish it clearly from both experimental and correlational research. Describe three different types of quasi-experimental research designs (nonequivalent groups, pretest-posttest, and interrupted time series) and identify examples of each one.

  4. Quasi-Experimental Design: Definition, Types, Examples

    Quasi-experimental design is a research methodology used to study the effects of independent variables on dependent variables when full experimental control is not possible or ethical. ... Evaluate Your Research Goals: Assess your research questions and objectives to determine which type of quasi-experimental design is most suitable. Each ...

  5. (PDF) Quasi-Experimental Research Designs

    Quasi-experimental research designs are the most widely used research approach employed to evaluate the outcomes of social work programs and policies. ... achieving its intended goal of preventing ...

  6. PDF Quasi-Experimental Designs

    The goal is to demonstrate that the two groups were as equal as possible before the change being studied took place. ... Qualitative research: A guide to design and implementation (4. th. ed.). Jossey-Bass, San Francisco, CA, USA. ... Experimental and quasi-experimental designs for generalized causal inference. Wadsworth Cengage Learning ...

  7. Experiments and Quasi-Experiments

    There are two basic types of research design: True experiments; Quasi-experiments; The purpose of both is to examine the cause of certain phenomena. ... so it becomes necessary to implement a quasi-experimental research design. Similarities between true and quasi-experiments: Study participants are subjected to some type of treatment or condition;

  8. How to Use and Interpret Quasi-Experimental Design

    A quasi-experimental study (also known as a non-randomized pre-post intervention) is a research design in which the independent variable is manipulated, but participants are not randomly assigned to conditions.. Commonly used in medical informatics (a field that uses digital information to ensure better patient care), researchers generally use this design to evaluate the effectiveness of a ...

  9. What is a Quasi-Experimental Design?

    Quasi-experimental design, a fascinating method in the realm of research, offers a unique approach to uncovering cause-and-effect relationships. Unlike traditional experiments, where researchers randomly assign participants to groups, studies work with real-world constraints, employing non-random criteria for group allocation.

  10. Quasi-experimental design

    Classification of quasi-experimental designs. Quasi-experimental designs fall into three categories: Non-equivalent groups design: This design involves the selection of two existing groups that are similar in some way to one another and assigning one as the control and the other as the treatment group of a study.Since the chosen groups are selected out of convenience and not as a result of ...