Three studies are reported which investigated the role of four variables in semantic generalization: Intentional versus Incidental learning instructions, associative and semantic relationships of the generalization stimuli (GSs) to the critical stimuli (CrSs), and rate of CrS presentation. (Author)

The objectives and methods of a free undergraduate laboratory are set forth. The main features are a close connection between the students and the research groups, a large amount of student freedom and responsibility, and no grading of the students. (Author/TS)

Discusses teaching ecology in high schools in terms of kinds of problems suitable for study and management of field and laboratory activities. (EB)

Presents the theoretical explanation of the observation that when a pen that is stuck in a hard rubber ball and dropped, the pen may bounce to several times the dropped height. Includes the procedure and models created to explain the observations. (DS)