A Quasi-Experimental Designs, Research Paper Example

What is different between a true experimental design and a quasi-experimental design?

The main difference between a true experimental and the quasi-experimental design is the allocation of treatments criterion. In the true experimental design participants or subjects are randomly allocated to treatment. However, in a quasi-experimental design allocation of treatment is through purposive sampling. Consequently, the main difference lies in the sample selection techniques. Essentially, manipulation of the internal variable remains the same for both experiments that.

Identify some possible confounds in each of the studies you outlined in your answers to Exercise 2 and Exercise 3. (Note: Please do not answer exercise 2 and 3, answer only this question.)

Exercise 2

A psychology professor is interested in whether implementing weekly quizzes improves student learning. She concluded that it does  improve student learning. Her experiment entailed administering weekly quizzes in one section of her introductory psychology class. The control class did not have these quizzes conducted every week. Which type of quasi-experimental design do you recommend for this study?

Exercise 3

If the psychology professor in Exercise 2 had access to only one section of introductory psychology, describe how she might use a single-group design to assess the effectiveness of weekly quizzes. Which of the three single-group designs would you recommend?

Give three reasons why a researcher might choose to use a single-case design?

Following are the reasons why a researcher might use a single case design:

• Single Case studies are appropriate in situations when a critical issue is represented for testing a formulated theory and has proven to be extremely unique. More so, a researcher can adopt a single design when the case requires scientific investigation.

In this type of design each subject is controlled by itself because it involvesa specific procedure. First, baseline functions are measured. Second, a solution is introduced and thirdly, its effect is measured. The solution thereafter is withdrawn and the baseline functioning is expected to be realigned.

The single-case design is important in explainingsituations where introduction of a solution requires drastic changes. Classic examples are exploring a cure for mental illness; investigating an herbal treatment for stimulating hair growth and researching anti-allergy treatments. The results can be explained in detail with careful attention to the research subjects.

How does a multiple-baseline design differ from a reversal design?

What is the difference in multiple base line design and Reversal Design?

In reversal designs the dependent variable is acted upon several times. This facilitates measuring the relationships between dependent on independent variables. During this phase of the experiment these measurements can be applied and later reversed. However, a multiple- baseline design are activated when reversal models are no longer applicable to the experiment. There could be ethical reasons for the reversal withdrawal model replacing it with multiple base line designs.

It must be emphasized thatin reversal designs a no-treatment baseline period is generally followed by a treatment baseline one whereby the target’s behavior is observed. Alternatively, in multiple baseline designs treatment results are derived  from different behavior as they are demonstrated successively.Also,reversal designs give results only for behavior changes occurring in apre-determined manner for each condition being investigated. A final difference is explained where multiple baseline designs measure outcomes at the beginning/ introduction of the independent variablemany times during the study.