Hinting by paraphrasing in an instruction system

Previous work has amphasized the need for paraphrases as means of ensuring a feedback with a system. In this paper, we discuss how a paraphrase may be used as a heuristic device, viz. as a hint. We describe an experimental instruction system in mathematics incorporating this feature. The system accepts a restricted class of algebraic story problems, formulated in non-stylized Bulgarian language, and is capable of solving them and providing one or more "hinting" paraphrases, that is, paraphrases alleviating their formalisation (-translation into equations).