Building Cognitive Tutors with Programming by Demonstration: When Simulated Students help Cognitive Modeling and Educational Studies

Carnegie Mellon University, Pittsburgh PA

Investigators

Abstract

This project will develop a novel design for an Intelligent Authoring System for Cognitive Tutors. The system includes a machine learning facility - called the Simulated Student - that generates a "cognitive model" which can perform the subject task just as students do. The Simulated Student learns the production rules in the cognitive model much like a human student: by observing examples of worked-out problem solutions, reading associated instructions, and getting feedback on solution attempts. The author provides the examples, English instructions, and solution feedback, and thus acts more like a teacher than a programmer. In this way, the Simulated Student allows authors to bypass the time-consuming and difficult-to-learn programming that is currently required to build the Cognitive Model component of a Cognitive Tutor. The key technology behind Simulated Students is programming by demonstration, in which machine learning is integrated tightly into a user interface. We plan to use learning methods based on Inductive Logic Programming and Statistical Relational Learning. With the proposed Intelligent Authoring System, an author will perform the following steps to build a tutor: (1) build a graphic user interface (GUI) for the tutor; (2) demonstrate solutions, by solving problems with the GUI and annotating steps with instructional messages, thus providing training data for the Simulated Student to learn production rules that replicate the demonstrations; and (3) test the production rules and giving the Simulated Student feedback on its solutions for another set of problems. This effort builds upon a suite of Cognitive Tutor Authoring Tools (CTAT), which includes a built-in GUI builder, a facility to demonstrate solution steps and recode them, and facilities to write and test production rules. The proposed Intelligent Authoring System will be implemented by integrating the Simulated Student into CTAT, so all three authoring steps will be a natural extension of existing authoring tools. This project has broader impacts in advancing intelligent systems technology and in providing better cognitive tutors by allowing teachers to be authors.