Characteristics of Participants and Nonparticipants in Experimental Research

Abstract

Characteristics of students who volunteered to participate in a laboratory experiment on group performance were compared with those of students who did not elect to participate. Subjects were 113 undergraduate students (65 men, 48 women; median age 23 yr.). There were no significant differences for the total sample between the participants and nonparticipants on locus of control, need for achievement, need for affiliation, age, or sex. Participation was, however, related to academic major, and male participants had higher need for achievement than male nonparticipants. Also, comparison of male and female subsamples with published national means indicated significant differences on need for achievement and need for affiliation. Male and female nonparticipants were higher than national means on need for achievement and lower than national means on need for affiliation. Need for achievement of male nonparticipants was lower than national means. Issues associated with volunteer bias are discussed and cautions raised.