Volunteer Bias in a Study of Sexual Knowledge, Attitudes, and Behavior

Some studies of sexual knowledge, attitudes, and behavior involve college students who volunteered to participate in the research. The present study assesses the impact of volunteer bias when considering random samples of an entire student body. The distribution of dependent variables differed only slightly when comparing volunteer and nonvolunteer samples; more differences were found when comparing them on key independent variables, and different conclusions were derived when correlating independent and dependent variables within volunteer and nonvolunteer samples in 7 of 23 comparisons for men, and 10 of 21 for women.