Subjects were 65 six-, eight-, ten-, and twelve-year olds from after-school day care programs. The subjects were unobtrusively observed in free play situations involving peers and the duration of their interactions in six types of peer groups of varying size were recorded. Subjects were also administered a picture card test, composed of 20 sets of cards representing six different types of peer groups engaged in particular activities; they were instructed to point out the one characteristic of them and their choices were recorded. The six peer group categories were hypothesized to be stages in children's peer relations but no clear patterns or emphasis on the types of peer groups were found with age. A correlation of 81 between scores derived from direct observation and those obtained using the picture test was found, suggesting the possibility of developing the picture test for future research or other purposes in lieu of lengthy direct observation. Sex did not interact with other variables. The major trends appeared to be towards increasing size and homogeneity of age and sex in preference of peer groups with increasing age in the subject. (Author)