1. An information processing device comprising: an inference unit that obtains inference results by applying inference rules to context information; an inference result index value calculation unit that, by using information that shows a reading user who reads the inference results, acquires a knowledge level of the reading user about each inference rule that was applied until the inference results are obtained, and on the basis of each knowledge level acquired, calculates index values that show depth of the knowledge of the reading user about the inference results comprehensively; an inference result presentation unit that presents the inference results on the basis of the index values calculated by the inference result index value calculation unit; and a knowledge level update unit that, for each inference rule that was applied until the inference results are obtained, updates the knowledge level of the reading user about the inference rule concerned on the basis of evaluation information in which the degree of the knowledge that the reading user possesses is evaluated about the inference results presented by the inference result presentation unit.