Affiliations: Learning Sciences Research Institute, University of
Nottingham, Jubilee Campus, Wollaton Road, Nottingham NG8 1BB, UK.
E-mail: ryan@educationaldatamining.org | Human-Computer Interaction Institute, Carnegie Mellon
University, 5000 Forbes Avenue, Pittsburgh, PA, 15213, USA. E-mail: {corbett,koedinger}@cmu.edu
Abstract: We present an approach to designing intelligent tutoring systems,
termed the Difficulty Factors Approach. In this approach, the designer
investigates, at each iteration of the design cycle, which skills and concepts
are difficult for students, and what factors underlie those difficulties. We
show that this approach complements existing design principles, producing data
that helps designers apply principles in context. We also show that by
continuing to investigate student difficulties throughout the design process,
it is possible to discover difficulty factors initially obscured by other
difficulty factors. We give an example of the application of the Difficulty
Factors Approach in the context of the development of a cognitive tutor lesson
on scatterplots.
