Inference results for which each user does not have detailed knowledge are presented with priority. An information processing device 1 includes: an inference unit 104 that obtains inference results by applying inference rules to context information; an inference result index value calculation unit 105 that calculates, on the basis of a knowledge level of a reading user about each inference rule used in an inference process, index values that show depth of knowledge of the reading user about the inference results comprehensively; an inference result presentation unit 106 that presents the inference results on the basis of the index values; and an knowledge level update unit 109 that updates the knowledge level of the reading user about each inference rule used in the inference process on the basis of evaluation information acquired.
Please help me write a proper abstract based on the patent claims. CLAIM: 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. 2. The information processing device according to claim 1, wherein the inference unit makes case information related to each inference rule that was applied until the inference results are obtained the inference results; and the inference result index value calculation unit calculates the index values for each case information as the inference results. 3. The information processing device according to claim 2, wherein the inference result index value calculation unit calculates the index values, in addition to the knowledge level of the reading user about each inference rule that was applied until the inference results are obtained, further on the basis of degree of importance of the case information as the inference results. 4. The information processing device according to claim 2, wherein the inference result index value calculation unit calculates the index values, in addition to the knowledge level of the reading user about each inference rule that was applied until the inference results are obtained, further on the basis of the knowledge level of the reading user about the case information as the inference results; and the knowledge level update unit further updates the knowledge level of the reading user about the case information on the basis of the evaluation information. 5. The information processing device according to claim 1, wherein the inference result index value calculation unit calculates the index values, in addition to the knowledge level of the reading user about each inference rule that was applied until the inference results are obtained, further on the basis of probability of occurrence of a phenomenon inferred by each inference rule. 6. The information processing device according to claim 1, wherein the knowledge level update unit executes the update using an increase/decrease value associated with classes of the evaluation information. 7. The information processing device according to claim 1 further comprising: an action history information conversion unit that converts, by applying action history conversion rules to action history information that shows action history of the reading user who read the inference results presented by the inference result presentation unit, the action history information concerned into the evaluation information. 8. An information processing system comprising: the information processing device according to claim 1; and a terminal that collects context information and sends it to the information processing device, outputs the inference results presented from the information processing device to an output device, and sends the evaluation information inputted from an input device to the information processing device. 9. An information processing method comprising: obtaining inference results by applying inference rules memorized in advance to context information inputted; acquiring a numerical value memorized in advance as a knowledge level that shows depth of knowledge that a reading user who reads the inference results possesses for each inference rule that was applied until the inference results are obtained, and calculating index values that show the depth of the knowledge of the reading user about the inference results comprehensively on the basis of each knowledge level acquired; presenting the inference results on the basis of the index values; acquiring, for the inference results presented, evaluation information in which degree of the knowledge that the reading user possesses is evaluated; and updating, for each inference rule that was applied until the inference results are obtained, a numerical value memorized as the knowledge level of the reading user about the inference rules concerned on the basis of the evaluation information. 10. A non-transitory computer-readable medium storing a computer program that makes a computer execute: a context information acquisition processing that acquires context information; an inference processing that obtains inference results by applying inference rules memorized in a memory device in advance to the context information; an inference result index value calculation processing that acquires a numerical value memorized in the memory device in advance as a knowledge level that shows depth of knowledge that a reading user who reads the inference results possesses for each inference rule that was applied until the inference results are obtained, and calculates index values that show the depth of the knowledge of the reading user about the inference results comprehensively on the basis of each knowledge level acquired; an inference result presentation processing that presents the inference results on the basis of the index values; an evaluation information acquisition processing that acquires, for the inference results presented by the inference result presentation processing, evaluation information in which degree of the knowledge that the reading user possesses is evaluated; and a knowledge level update processing that updates, for each inference rule that was applied until the inference results are obtained, a numerical value memorized in the memory device as the knowledge level of the reading user about the inference rule concerned on the basis of the evaluation information.