Plan Recognition Problem

• It is likely that the student wants a hint on how to do that step correctly. If the tutor can determine which correct step corresponds to the incorrect step entered by the student, then it can safely hint that correct step. On the other hand, if the tutor cannot determine which correct step corresponds to the student’s step, the tutor may ask the student what step they were trying to enter. Andes does this for unrecognizable equations that the student wants help on.
• If none of these simple cases apply, then the tutoring system has to somehow figure out which of the possible next steps is most likely to be part of the solution that the student is trying to pursue.
• (Russell & Norvig, 2003)
• The general idea is to match the sequence of steps leading up to the most recent student step against step sequences that are either generated by a planner or pulled from a plan library. Once the tutor has determined the plan that the student seems to be following, then it can easily determine what the next step in that plan is.