Understanding Quasi-Experimental Design in Research

A quasi-experimental design is a research method that uses a non-experimental variation in the main independent variable of interest, emulating experimental conditions in which some subjects are exposed to treatment, and others are not on a random basis.

Quasi experimental design involves the manipulation of the independent variable without the randomized assignment of participants to conditions. If you are in search of expert guidance on the quasi-experimental design in research, our professionals determine the cause-and-effect relationship of variables using criteria rather than randomization. This post is a comprehensive guide to the quasi-experimental design, highlighting its characteristics, types, benefits, when to use, and examples for reference.

What is a Quasi-Experimental Design in Research?

The quasi-experimental design is a research method that lacks the element of random assignment. It involves setting up an experiment where the researcher has little to no control over the factors being studied. Below are key characteristics of quasi-experimental design:

• The main characteristic of quasi-experimental design is novelty. Novelty is the contribution of new information to an existing field of research.
• This design involves the use of designs like interrupted time series design and multiple time series design.
• Another characteristic is originality. The researcher uses innovative procedures to come up with original results crucial for decision-making.

Benefits of Quasi-Experimental Design

• In fields such as social science, where pre-selection of groups can be challenging, quasi-experimental designs are useful in achieving results to identify general trends. For example, a researcher may want to know the impact of consuming alcohol on expectant mothers. They would choose a group of people and ask them how much alcohol they consumed, then put them in groups.
• Quasi-experimental designs do not require pre-screening and randomization, so they save on the time and resources that would have been used to conduct these activities.
• Quasi-experimental designs are easier to set up than experimental designs because randomization is practically impossible.
• The findings of a quasi-experimental design can be applied in other settings hence allowing researchers to make conclusions about a certain population.

When to use a quasi-experimental design

• When the study is not ethical, but the researcher wants to know the cause-and-effect relationship of the variables. For example, it would be unethical to research the effects of COVID-19 by choosing random people to infect with the virus.
• A researcher can use this design when it is difficult or impossible for variables to be assigned at random. For example, evaluating the effects of a situation such as a war or national disaster.
• Researchers can also use quasi-experimental designs where the time and resources are limited and doing a real experiment would be costly.

What Distinguishes an Experiment from a Quasi-experimental Design?

The word ‘quasi’ means resembling. Thus a quasi-experimental design is one that resembles a true experiment but lacks some of its key characteristics. It is a quantitative research procedure where the researcher must select subjects of research from preexisting groups to conduct their study.

The key characteristics that distinguish an experiment from a quasi-experimental design are that in a true experiment, the researcher has full control of the study, while in a quasi-experimental, the experimenter lacks control of the study. Also, a true experimental design involves the manipulation of variables contrary to a quasi-experimental, where the researcher cannot manipulate the variables but instead observes the categories of the subjects under study.

Types of Quasi-Experimental Design

Research designs are used to assess the effectiveness of an action, for example, health programs or educational practices. There are multiple kinds of quasi-experimental research designs. The types of quasi-experimental design include:

(1). Non-Equivalent Group, Posttest-Only Design

The non-equivalent group, posttest-only design of quasi-experimental research design involves measuring the results of two groups where only one of the groups has undergone the treatment. For example, a professor can choose two of their classes and administer different learning programs to each. One group of students can learn through online classes, while the others can use physical classes. After a month or two, they can administer tests to see which method is more effective in delivering results.

(2). Non-equivalent Control Group Design

In the non-equivalent control group design, the researcher compares a control and an experimental group. The groups are not randomized but are chosen out of convenience. In this design, for example, the professor would use the teaching method under study on only one group of students and then measure the results after the preferred period to measure its effectiveness.

(3). Interrupted Time Series Design

The interrupted time series design allows the same group under study to be compared over time by assessing the trend before and after they are subjected to treatment. In this design, pre-testing and post-testing are done at intervals. For example, a researcher may want to hold a campaign to reduce alcohol consumption in a group of people in October. They would collect data on people drinking before October, then hold the campaign and continue collecting data after October.

The researcher can identify the trend in alcohol consumption rates before and after the campaign to assess whether it had an impact.

(4). Multiple Time Series Design

In the multiple time series design, there are two groups under research. One group gets treatment, and the other is not subjected to treatment and acts as a control. The multiple time series quasi-experimental research design is mostly used in complex settings.

(5). Repeated Treatment Design

The repeated treatment design is a quasi-experimental research method where a group of participants is exposed to multiple conditions of the same variable. Through evaluating the effects of the repeated administration of the treatment, the researcher identifies the effects of both variables on each other. A major advantage of the repeated treatment design is that it ensures accuracy by preventing the range of individual differences.

(6). Examples of Quasi-Experimental Design

Quasi-experimental designs are applied in a wide range of social and behavioral sciences including in the fields of economics, education, medicine, public health, sociology, and so much more. Below are detailed examples of real-life applications of this design:

Example 1

Exploring the effect of a new marketing choice

A company may want to test the impact of adopting a new marketing strategy on sales of the company. The researcher would conduct a quasi-experimental design to get reliable results crucial for decision-making. So, in this situation, the company would implement this design by:

Selecting one group of customers based on factors such as purchasing methods and history and using the new marketing strategy on them while using the old strategies on a different group of customers. The company can then use the new sales digits to compare with the old numbers to gauge the effectiveness of the new marketing strategy.

Example 2

Evaluating the effectiveness of new treatment procedures

A hospital may want to research if a new treatment method is working on their patients. They would expose some patients to a new treatment method while using the same old one on a different set of patients. They would then check the differences and trends in the results to know the effectiveness of the treatment.

Example 3

Assess the effects of big social interventions such as recessions on the economy

In the field of economics and social sciences, a researcher may want to know the impact of interventions, for instance, wars or recessions on the economy. Conducting a real experiment in this situation would be impractical, so the researcher would use a quasi-experimental design. The most suitable type of quasi-experimental design for this situation would be the interrupted time series design.

Why Should I Get Help with Quasi-experimental Design?

• Quasi-experimental design usually involves research in the real world where ethical rules apply. Experts are familiar with the regulations for conducting ethical research hence making the process easier.
• Quasi-experimental design research does not involve randomization when choosing subjects. Expert researchers are in a better position to choose the subjects to conduct research on for accurate, reliable results.
• After carrying out research, data acquired must be analyzed to acquire results for making conclusions. The procedures used in statistical analysis, such as 2-group tests and regression analysis of quasi-experimental design, are somewhat complex, requiring someone with technical knowledge of the procedures.
• Professional experts can assist you in reporting the results of your analysis for easy understanding of the reader.
• Getting help with conducting a quasi-experimental design in research can save you a lot of time and resources that would have been used to conduct the research.

Why We Are the Best Quasi-Experimental Design Services

• Our researchers have extensive experience with conducting quasi-experimental design research, assuring our clients of quality results.
• Our services have a proven track record of successful research projects proven by the positive client reviews on our website.
• Our services offer customized quasi-experimental design services to our clients. We have experts experienced in every field of research who can handle your request.
• We have an excellent customer service team available 24/7  to respond to your inquiries promptly via our live chat or email and to update you on the progress of your order.

Summary

A quasi-experimental design is a systematic quantitative research method where the researcher uses pre-existing groups to conduct their study. A researcher can conduct this type of design when the study is unethical, where there is a limitation of resources, and the variables cannot be randomized.

Conducting a quasi-experimental design in research can be a time-consuming process requiring technical know-how of the research process. Hiring quasi-experimental design services can be a strategic move that assures you of timely delivery without compromising on quality. So, why stress about your research when that’s our job? Reach out to us now by contacting us or join our live chat to talk to one of our agents to get help.