One of the most fundamental problems in education in Korea up to yet is that teaching-learning activities in the classroom are carried out without considering each student\`s interest, ability aptitude and other attributes. In 1995, National committee on Educational Reform of Korea recommended big changes on various aspects of the education system of the nation. In 1997, just before so-called the \"International Monetary Fund (IMF) crisis \" in Korea, Ministry of Education announced the seventh amendment of national curriculum. The foundation of new national curriculum is the implementation of a \"differentiated\" curriculum. Also, the new curriculum strongly suggests \"performance assessment\", which was introduced to the nation in mid 1990\`s. However, most mathematics teachers have reluctant to both new curriculum and performance assessment.