Simulated Student: Building Cognitive Model by Demonstration

1. Simulated Student: Building Cognitive Model by Demonstration Noboru Matsuda School of Computer Science Carnegie Mellon University

2. CTAT: Cognitive Tutor Authoring Tools No programming at all for Example-Tracing Tutors A cognitive model specific to a particular problem For Model-TracingTutors, the author must build a generalized cognitive model Writing production rules is challenging Cognitive task analysis is also challenging Performing a task is much easier…

3. SimStudent Machine learning agent that … Observes model solutions Learns problem-solving steps Outputs a set of production rules Model of human students learning cognitive skills Programming by Demonstration } Both for correct and incorrect steps Lau, T. A., & Weld, D. S. (1998). Programming by demonstration Blessing, S. B. (1997). A programming by demonstration authoring tool for model-tracing tutors

4. Next Generation Authoring Build a tutor GUI Demonstrate a solution SimSt. learning Production Rules Rule simplify-LHS: IF is-equation( Eq ), is-lhs( Eq, Lhs ), polynomial( Lhs ), all-var-terms( Lhs ) Then simplify( Lhs, S-lhs ), enter( S-lhs ) Rule simplify-LHS: IF is-equation( Eq ), is-lhs( Eq, Lhs ), polynomial( Lhs ), all-var-terms( Lhs ) Then simplify( Lhs, S-lhs ), enter( S-lhs ) Rule simplify-LHS: IF is-equation( Eq ), is-lhs( Eq, Lhs ), polynomial( Lhs ), all-var-terms( Lhs ) Then simplify( Lhs, S-lhs ), enter( S-lhs )

5. No Free Lunch Background knowledge Operators Feature predicates External Jess function written in Java (defrule multi-lhs … ?var22140 <- (column (cells ? ? ?var22143 ? ? ? ? ?)) ?var22143 <- (cell (value ?val0&~nil)) (test (fraction-term ?val0 )) => (bind ?val2 (denominator ?val0)) (bind ?input (mul-term-by ?val0 ?val2)) … )

6. Example: Stoichiometry Tutor

7. Learn more about Simulated Students Tutorial http://ctat.pact.cs.cmu.edu/tutorials/2.2/simst-interactive-learning Send email to Noboru at mazda@cs.cmu.edu