Experiental Research-Matched Group Design

MATCHED GROUPS DESIGN
• A matched groups design may be used to create comparable groups when there are too few subjects available
for random assignment to work effectively.
• Matching subjects on the dependent variable task is the best approach for creating matched groups, but performance on any matching task must correlate with the dependent variable task.
• After subjects are matched on the matching task, they should then be randomly assigned to the conditions of the independent variable.
The matched groups design is a good alternative when neither the random groups design nor the repeated measures design can be used effectively. The logic of the matched groups design is simple and compelling.
Instead of trusting random assignment to form comparable groups, the researcher makes the groups equivalent by matching subjects. Once comparable groups have been formed based on the matching, the logic of the matched groups design is the same as that for the random groups design In most uses of the matched groups
design, a pretest task is used to match subjects. The challenge is to select a pretest task (also called a matching task) that equates the groups on a dimension that is relevant to the outcome of the experiment. The matched groups design is useful only when a good matching task is available.