ABSTRACT
The element of time is important in social research. Repeated measures of a concept permit assessment of reliability and validity. Whether one variable precedes the other in time cannot always be determined in cross-sectional research. The advantages of cross-sectional research include lower costs associated with time and money, and fewer chances for research subjects to drop out of the study. A limitation is that firm statements about the causal order of variables are more difficult to establish. Longitudinal studies provide data from two or more points in time. Data can be collected from the same subjects, from members of the same cohort but not the same subjects, and from different cohorts and subjects but on the same topic. Personal acceptance of gay identity, being in a committed gay relationship, the proportion of family members respondents talked to about acquired immune deficiency syndrome, and self-esteem all showed positive associations, while depression showed a negative relationship with total social support.
