This study examines developmental change across adolescence in the similarity of friends versus nonfriends. This differential in similarity is a key aspect of the organization of the peer context of development: The stronger the correlation between friends for an attribute, the more the attribute delineates clustering and divisions of friendships.…

The purpose of this study is to compare changes in attitudes of students about their study of biology in the classes thought by five biology teachers who experienced an Iowa Chautauqua workshop with and two non-Chautauqua teachers who had no experience with any professional development program. The results indicated that there are significant…