...Factors Analysis ndash; A General Method for Cognitive Model ...课件.ppt

Learning Factors Analysis – A General Method for Cognitive Model Evaluation and Improvement Hao Cen, Kenneth Koedinger, Brian Junker Human-Computer Interaction Institute Carnegie Mellon University 精品文档 Learning curve analysis by hand eye … Steps in programming problems where the function (“method”) has two parameters (Corbett, Anderson, O’Brien, 1995) 精品文档 Can learning curve analysis be automated? Learning curve analysis Identify blips by hand eye Manually create a new model Qualitative judgment Need to automatically: Identify blips by system Propose alternative cognitive models Evaluate each model quantitatively 精品文档 Overview A Geometry Cognitive Model and Log Data Learning Factors Analysis algorithm Experiments and Results 精品文档 Domain of current study 15 skills Circle-area Circle-circumference Circle-diameter Circle-radius Compose-by-addition Compose-by-multiplication Parallelogram-area Parallelogram-side Pentagon-area Pentagon-side Trapezoid-area Trapezoid-base Trapezoid-height Triangle-area Triangle-side Domain of study: the area unit of the geometry tutor Cognitive model: 精品文档 Log Data -- Skills in the Base Model Student Step Skill Opportunity A p1s1 Circle-area 1 A p2s1 Circle-area 2 A p2s2 Rectangle-area 1 A p2s3 Compose-by-addition 1 A p3s1 Circle-area 3 精品文档 Overview Cognitive Models Cognitive Tutors Literature Reviews on Model Improvement A Geometry Cognitive Model and Log Data Learning Factors Analysis algorithm Experiments and Results 精品文档 Learning Factors Analysis Statistics Combinatorial Search Difficulty Factors a set of factors that make a problem-solving step more difficult for a student Logistic regression, model scoring to fit statistical models to student log data A* search algorithm with “smart” operators for proposing new cognitive models based on the factors 精品文档 The Statistical Model Probability of getting a step correct (p) is proportional to: if student i performed this step = Xi, add overall “smarts” of that student = ?i if