Quasi-experimental design differs from true experimental design in that it does not use random assignment of participants to experimental groups. Instead, participants are placed in groups based on other criteria. Quasi-experiments aim to establish cause-and-effect relationships between independent and dependent variables like true experiments, but lack random assignment. There are three key aspects of experimental design - manipulation of the independent variable, random assignment of participants, and use of a control group. Quasi-experiments approximate these aspects using techniques like non-equivalent group design and regression discontinuity design.

1. Quasi-Experimental Design
Presented by:
Shadan H. Malangkapi
MAT English

2. What Is Quasi-Experimental Design?
• random assignments, the participants are placed in the
experimental groups based on some of the other criteria.
• manifest the cause-effect relationship between the independent
and dependent variable

3. Experimental design has three
characteristics:
•Manipulation
•Randomization
•Control

4. Manipulation
• Manipulation simply means, evaluating the effect of the
independent variable on the dependent variable.

5. Randomization
• Select a sample without any plan and everyone has an equal
chance of getting into any one of the experimental groups.

6. Control
• Using a control group in the experiment. In this group, researchers
keep the independent variable constant. This control group is then
compared to a treatment group, where the researchers have
changed the independent variable

7. Control
• Treatment group: You pay more to the workers
Control group: You don’t pay any extra to the workers and things
remain the same.

8. Differences Between Quasi-Experiments and
True Experiments

9. Example of a True Experiment vs a Quasi-
Experiment
Example of a true experiment
•Study the effect of junk food on obese people.
Example of quasi-experiment
Existing groups to the participants according to their choices. Study
how the regular consumption of junk food affects the obese from
that group.

10. Types of Quasi-Experimental Design
• Non-equivalent group design (NEGD)
Uses the pre-existing groups that we feel are similar, namely
treatment and control groups. But it lacks the randomization
characteristic of a quasi-experiment
Regression discontinuity design or RDD
is a quasi-experimental design technique that computes the
influence of a treatment or intervention