ABSTRACT
This chapter focuses on providing evidence specifically for ACT-R to a focus on providing evidence for the general utility of production rules for understanding skill acquisition. It presents few connections with the specifics of ACT-R; most of the results would be relevant to most production-system theories. The chapter reports on the authors' research with the geometry tutor. It looks at the data the geometry tutor has provided about the nature of the acquisition of problem-solving skill. The chapter notes the authors' view is that the data from the geometry tutor have less to say about the specifics of ACT-R, and more to say about the nature of geometry proof skill and about a production-rule analysis of this skill more generally. In broad outline, the analysis of the data from the geometry tutor is consistent with the data from the LISP tutor and has given support to the ACT-R theory.
