1.Fraction Subtraction Data 数据描述：
536个学生做20道关于分数减法的响应数据集
20道题涉及的8个知识点：
alpha1 convert a whole number to a fraction, alpha2 separate a whole number from a fraction, alpha3 simplify before subtracting, alpha4 find a common denominator, alpha5 borrow from whole number part, alpha6 column borrow to subtract the second numerator from the first, alpha7 subtract numerators, alpha8 reduce answers to simplest form
20道题题目描述：
Q-matrix:
解释：如item1，即题目1涉及的知识点为alpha4，alpha6,alpha7,对应的实际考察的知识点为： find a common denominator, column borrow to subtract the second numerator from the first, subtract numerators
2.TIMSS 2003 数据描述：
2003年8年级的数学测试
涉及了23道题，考察了15个知识点
Q-matrix:
wait to continue。。。 Reference: - DeCarlo, Lawrence T. “On the analysis of fraction subtraction data: The DINA model, classification, latent class sizes, and the Q-matrix.” Applied Psychological Measurement (2010). 分数减法数据来源 - Su, Y.-L., Choi, K. M., Lee, W.-C., Choi, T., & McAninch, M. (2013). Hierarchical cognitive diagnostic analysis for TIMSS 2003 mathematics. CASMA Research Report 35. Center for Advanced Studies in Measurement and Assessment (CASMA), University of Iowa. TIMSS Dataset （介绍了DINA、DINO模型）
