2Hmelo, C. E. , Ferrari. The problem - based learning tutorial: Cultivating higher order thinking skills[ J]. Journal of the Education of the Gifted, 1997, 20(4) : 401 -422.
3Lovett, M. C. , Schunnd, C. D. Task representation, strategy variability, and basic - rate neglect [ J ]. Journal of experimental psychology: General, 1999, 128(2): 107-130.
4Hmelo, C. E. Problem - based learning: Effects on the early acquisition of cognitive skill in medicine [ J ]. The Journal of the Learning Science, 1998, 7(2) : 173 -208.
5Wertheimer, M. A gestalt perspective on computer simulations of cognitive processes [ J ]. Computer in human behavior, 1985, 1:19-33.
6Zhang J. The nature of external representation in problem solving [ J]. Cognitive science, 1997, 21 (2) : 179 - 217.
7Lawson,M. J. , Chinnappan, M. Generative activity during geometry problem solving: comparison of the performance of high - achieving and low- achieving students[ J ]. Cognition and instroction, 1994, 12:61-93.
8Boshuizen, H. P. A. , Schmidt, H. G. , Wassmer, L. Curriculum style and the integration of biomedical and clinical knowledge [ J]. Paper presented at the Second International Symposium on Problem-based Learning. Yogyakarta, Indonesia. 1990.
