Active learning in this domain typically uses text problems. Furthermore, the curriculum is algorithmically tractable and thus forms an appropriate base for this research. Text problems consist of problem texts that informally describe the problem structure. Formalisation means building a formal model from this textual information. The model is thus a structured representation of the unstructured textual representation.
Emphasis is on multi-level hints, demonstrations, and explanations.
The latter is based on the former. Other ITSs separate the textual representation, thus introducing sources for inconsistencies. It is possible to extend this concept and to apply it to other domains by including different types of information.