This article reports a design experiment conducted over three successive school years, with the teacher's goal of having his Grade 4 students assume increasing levels of collective responsibility for advancing their knowledge of optics. Classroom practices conducive to sustained knowledge building were co-constructed by the teacher and students,…

Average-ability students often do not take full advantage of learning in mixed-ability groups because they hardly engage in the group interaction. This study examined whether structuring collaboration by group roles and ground rules for helping behavior might help overcome this participatory inequality. In a plant biology course, heterogeneously…

Presents the results of an ethnographic study of cooperative learning experiences in one fourth- and one fifth-grade classroom. Describes the types of conflicts which arose during group work and offers four guidelines for making cooperative learning experiences more successful. (JDH)

Reports contemporary data concerning the fear of nuclear war among Americans of different age groups. Identifies recent efforts to educate K-12 students about the threat of nuclear war. (JDH)