Ninth Edition CoverGraziano & Raulin
Research Methods (9th edition)

Designing Differential Studies and 
Selecting Appropriate Comparison Groups

Designing differential research studies that are effective in answering research questions and controlling most sources of confounding involved recognizing the most likely sources of confounding and selecting comparison groups that are effective in controlling the confounding. 

For each of the research questions below, (a) identify the likely sources of confounding, (b) identify suitable comparison group(s) that are likely to control that confounding, and (c) search the research literature to see if your choices for 1 and 2 are consistent with what other researchers have done.

  1. You want to study the impact on family cohesion of having a child with attention-deficit/hyperactivity disorder (ADHD).

  2. You want to investigate the unique impact of losing a family member in a terrorist attack.

  3. You are interested in the long-term impact of marijuana use on cognitive functioning and memory.

  4. You want to study the influence of birth order on assertiveness, drive to succeed, and confidence in social relationships.

  5. You believe that spending time in the military gives people a different perspective on social issues. You want to study this possibility in a group of people who spent one tour of duty in the military.