Reports a study of 913 Israeli students in grades 7-12 from randomly chosen heterogeneous homeroom classes to investigate students' Piagetian cognitive levels using a video-based test. Results indicate that less than 50 percent of high school students have mastered formal operational reasoning. (MDH)

Whether or not the spatial cognitive development of students from distinct social-cultural milieus, specifically Anglos from the southwestern part of the United States and Native Turks, would proceed along approximately the same lines was investigated. The overall findings tend to indicate that at times the acquisition of spatial structures may be…