Constraint-based Modeling and Ambiguity
In IJAIED
16 (1)
Publication information
Abstract
Constraint-based modeling has been used in many application areas of Intelligent Tutoring Systems as
a powerful means to analyse erroneous student solutions and generate helpful feedback. In contrast to domains
where the structure of the problem under consideration allows a constraint to (almost) uniquely determine the
possible cause of a particular student error, there are other applications where a multitude of competing error
explanations has to be considered. In such cases constraint-based models alone hardly meet the requirements
for a student model. Instead a constraint-based model clearly serves the purpose of error diagnosis and needs
to be complemented by additional components for diagnosis selection based on general or individually tailored
heuristics. By investigating the apparent and strong parallelism between constraint-based modeling and modelbased
diagnosis, this paper identifies four major sources of ambiguity that need to be considered when using
constraint-based modeling and describes options for dealing with situations in which alternative error descriptions
are available. Examples are primarily drawn from the area of foreign language learning.
