Modeling Hinting Strategies for Geometry Theorem Proving

This study characterizes hinting strategies used by a human tutor to help students learn geometry theorem proving. Current tutoring systems for theorem proving provide hints that encourage (or force) the student to follow a fixed forward and/or backward chaining strategy. In order to find out if human tutors observed a similar constraint, a study was conducted with students proving geometry theorems individually with a human tutor. When working successfully (without hints), students did not consistently follow the forward and/or backward chaining strategy. Moreover, the human tutor hinted steps that were seldom ones that would be picked by such tutoring systems. Lastly, we discovered a simple categorization of hints that covered 97% of the hints given by the human tutor.