6Leonard W. New challengesfor science, technology and society education. Available online,2002,7 (2) : 174-177.
7Prince K J, Van Eijs PW, Boshuizen HP,et al. General competencies of problem-based learning (PBL) and non-PBL graduates. Medical Education, 2005,39 (4) : 394 -401.
8Alter JA,Spandel V. Using porffohos of student work in instruction and assessment. Educational Measurement:Issue and Practice, 1992,11 (1):36-44.
9Mullin JA. Portfolio:purposeful collections of student work. New Di- rections for Teaching and Learning, 1998,14: 74- 87.
