One way of classifying various group research designs is to place them into the categories of (1) preexperimental designs, (2) quasi-experimental designs, and (3) experimental designs. Describe the distinction between these categories of research designs and give one example of each type.

Question

What will be an ideal response?

Answer 1

Ans: Preexperimental research designs do not address any of the threats to internal validity. Some examples of preexperimental designs are the one-group pretest–posttest design and the one-group posttest-only design. Quasi-experimental research designs control for some of the threats to internal validity but are not as good at this as the experimental research designs. These designs typically compare two groups of people, some with the treatment and some without it (or an alternative treatment). This comparison gives the quasi-experimental designs the advantage (over the preexperimental designs) of having a basis for computing the effect of maturation upon the target behavior. Included among the quasi-experimental research designs are the comparison group design and the alternative treatment design. Experimental research designs have an optimal approach to controlling for threats to internal validity. They tend to control for all of the threats that are likely to be a concern for the social work researcher, and they control for these threats in a better way than is the case of the quasi-experimental designs because the experimental research designs use random assignment of people to treatment and control groups.
Learning Objective: 14-3: Describe the various threats to internal validity
Cognitive Domain: Comprehension
Answer Location: Group Research Designs.
Difficulty Level: Hard