Using Logistic Regression to Trace Multiple Sub-skills in a Dynamic Bayes Net.
Yanbo Xu, Jack Mostow · 2011
A challenge in estimating students ’ changing knowledge from sequential observations of their performance arises when each observed step involves multiple subskills. To overcome this mismatch in grain size between modelled skills and observed actions, we use logistic regression over each step’s subskills in a dynamic Bayes net (LR-DBN) to model transition probabilities for the overall knowledge required by the step. Unlike previous methods, LR-DBN can trace knowledge of the individual subskills without assuming they are independent. We evaluate how well it fits children’s oral reading fluency data logged by Project LISTEN’s Reading Tutor, compared to other methods. Key terms: dynamic Bayes net, logistic regression, knowledge tracing, multiple subskills, oral reading fluency