This module will focus on the selection of human research populations and subjects within these populations for inclusion in behavioral, social science, and biomedical research studies. Federal regulations require the equitable selection of research subjects. The goal of equitable selection is to fairly distribute the risks and benefits of research across society. In order to produce generalizable results, the subjects selected must be representative of the population about which new knowledge is being sought.

The subject population for the research study must be described in terms as precise as permitted by the measurements used for their selection. The first priority in subject selection should be that subjects have the biological, social, or behavioral attributes that will enable the investigator to accomplish the goal(s) of the research protocol. The second priority is to select a population that is least vulnerable to harm from the research interventions or procedures. The third priority is to select a population that is the least vulnerable population necessary to accomplish the goals of the research (see Module #7 for discussion of vulnerable subjects). If the subjects to be selected must be vulnerable, it is necessary to satisfy the regulatory and ethical criteria for justification of involving vulnerable populations. Thus, the criteria for selection must be responsive to norms calling for good research design, a favorable balance of harms and benefits, and equitable selection of subjects.