A leader in the development of constmctivist leaning environments is the Cognition and Technology Group at Vanderbilt (CTGV). Through the Jasper Woodbury series of videod disc-based leaning materials, environments for science and mathematical problem solving have been created based on three building blocks: generative learning, anchored instruction. and cooperative learning (CTGV,19993). These three building blocks provide a helpful structure for describing the lrey characteristics of cunstmctivist teaning environments.