Members of racial and ethnic minority groups are vulnerable research subjects in two respects: overrepresentation and underrepresentation. On the one hand, members of minority groups should not be over-included in research out of mere convenience or availability. No group of persons should be asked to bear the risks of research when many groups will share the benefits of that research. On the other hand, members of minority groups should not be excluded from research out of mere convenience or availability. For generalizability of research findings, investigators must include the widest possible range of population groups. Therefore, investigators must provide a “clear compelling rationale for their exclusion or under representation” of minority group members from research.