User Modeling and User-Adapted Interaction

, Volume 4, Issue 4, pp 253–278

Knowledge tracing: Modeling the acquisition of procedural knowledge

  • Albert T. Corbett
  • John R. Anderson

DOI: 10.1007/BF01099821

Cite this article as:
Corbett, A.T. & Anderson, J.R. User Model User-Adap Inter (1994) 4: 253. doi:10.1007/BF01099821


This paper describes an effort to model students' changing knowledge state during skill acquisition. Students in this research are learning to write short programs with the ACT Programming Tutor (APT). APT is constructed around a production rule cognitive model of programming knowledge, called theideal student model. This model allows the tutor to solve exercises along with the student and provide assistance as necessary. As the student works, the tutor also maintains an estimate of the probability that the student has learned each of the rules in the ideal model, in a process calledknowledge tracing. The tutor presents an individualized sequence of exercises to the student based on these probability estimates until the student has ‘mastered’ each rule. The programming tutor, cognitive model and learning and performance assumptions are described. A series of studies is reviewed that examine the empirical validity of knowledge tracing and has led to modifications in the process. Currently the model is quite successful in predicting test performance. Further modifications in the modeling process are discussed that may improve performance levels.

Key words

Student modelinglearningempirical validityprocedural knowledgeintelligent tutoring systemsmastery learningindividual differences

Copyright information

© Kluwer Academic Publishers 1995

Authors and Affiliations

  • Albert T. Corbett
    • 1
  • John R. Anderson
    • 2
  1. 1.Human Computer Interaction Institute, School of Computer ScienceCarnegie Mellon UniversityPittsburghUSA
  2. 2.Psychology and Computer Science DepartmentsCarnegie Mellon UniversityPittsburghUSA