Question

In what way does quasi-experimental design differ from experimental design?

Answer 1

Quasi v/s Experimental Design

1. One of the most obvious and important difference between the two designs is that in a quasi experimental design the subjects aren’t randomly assigned while in a true experimental design the subjects in both the control(s) and experimental group are randomized. Randomization of sample signifies that every subject has an equal chance of being a part of any of the groups in a study.
2. The quasi design leads to an associative or correlative inference about a study, while in an experimental design there is a cause and effect relationship between variables.
3. Quasi designs also have limited validity and reliability due to issues with potential bias, non randomization and other elements that are require for making unbiased and scientific facts/enquiries or results. However due to control and manipulation of independent variable, randomization, focus on extraneous variables and other factors in an experimental design; it is regarded as a scientific study that helps in yielding various inferences, conclusions and results.
4. Quasi designs can have limited participants and are most viable ethically in some form of enquiries and testing. For e.g. studies relating to soldiers, or a treatment for people suffering from mouth cancer, etc. wherein randomization isn’t viable, quasi experiment are useful to provide basic conclusions or inferences. While experimental designs usually have a large sample and larger the sample or duplication of similar results, the better the reliability and validity of a given experiment. For e.g. checking for people’s view in a given country on live-in relationships, or study on city college students awareness about internet addiction, etc.?
5. Quasi experiments can help yield data and focus for furthering a topic, method or study in a given direction to be conducted through a true experimental design. However a vice-versa situation is very limited to occur.