Affiliations: Computer Science Department, Worcester Polytechnic
Institute, Worcester, MA 01609, USA. E-mail: {nth,leenar}@wpi.edu | School of Computer Science, Carnegie Mellon
University, Pittsburgh, PA 15213, USA. E-mail: koedinger@cmu.edu
Abstract: Following Computer Aided Instruction systems, 2nd
generation tutors are Model-Tracing Tutors (MTTs) (Anderson & Pelletier,
1991) which are intelligent tutoring systems that have been very successful at
aiding student learning, but have not reached the level of performance of
experienced human tutors (Anderson et al., 1995). To that end, this paper
presents a new architecture called ATM ("Adding a Tutorial
Model"), which is an extension to model-tracing, that allows
these tutors to engage in a dialog that is more like those in which experienced
human tutors engage. Specifically, while MTTs provide hints toward doing the
next problemsolving step, this 3rd generation of tutors, the ATM architecture,
adds the capability to ask questions towards thinking about the knowledge
behind the next problem-solving step. We present a new tutor built in ATM,
called Ms. Lindquist, which is designed to carry on a tutorial dialog about
algebra symbolization. The difference between ATM and MTT is the separate
tutorial model that encodes pedagogical content knowledge in the form of
different tutorial strategies, which were partially developed by observing an
experienced human tutor. Ms. Lindquist has tutored thousands of students at
www.AlgebraTutor.org. Future work will reveal if Ms. Lindquist is a better
tutor because of the addition of the tutorial model.
