An inference device disclosed herein includes an identifying unit, and an inferring unit. The identifying unit identifies a set of a predetermined phenomenon, an effect having a causal relation with the predetermined phenomenon, and a polarity of the effect, from concept information in which a phenomenon, an effect having a causal relation with the phenomenon, a polarity to be an indicator of advantages and disadvantages caused by the effect to a user. The inferring unit infers an effect caused when the predetermined phenomenon occurs, and advantages and disadvantages caused by the effect based on the set identified by the identifying unit.
Please help me write a proper abstract based on the patent claims. CLAIM: 1. An inference device comprising: an identifying unit that identifies a set of a predetermined phenomenon, an effect having a causal relation with the predetermined phenomenon, and a polarity of the effect, from concept information in which a phenomenon, an effect having a causal relation with the phenomenon, a polarity to be an indicator of advantages and disadvantages caused by the effect to a user; and an inferring unit that infers an effect caused when the predetermined phenomenon occurs, and advantages and disadvantages caused by the effect based on the set identified by the identifying unit. 2. The inference device according to claim 1, wherein the identifying unit identifies a phenomenon that is a combination of a predetermined subject and a predetermined event relating to the predetermined subject, as the predetermined phenomenon. 3. The inference device according to claim 2, wherein the identifying unit identifies a set of the predetermined phenomenon, a polarity of an event included in the phenomenon, an effect having a causal relation with the predetermined phenomenon, and a polarity of the effect, from concept information in which a polarity to be an indicator of advantages and disadvantages caused by the event to a user is further associated, and the inferring unit infers advantages and disadvantages to the user based on the polarity of the event and the polarity of the effect included in the set identified by the identifying unit. 4. The inference device according to claim 2, wherein the inferring unit infers, when the effect inferred based on the set identified by the identifying unit causes a disadvantage to the user, any one of an effect and an event to inverse the disadvantage caused when the predetermined phenomenon occurs, by using pair information in which any one of events and effects having paired concepts are associated with each other. 5. The inference device according to claim 4, wherein the inferring unit searches for a phenomenon that is a phenomenon corresponding to an effect included in the set identified by the identifying unit and that is not included in the set identified by the identifying unit from the concept information, and infers a phenomenon in which an event included in the searched phenomenon is replaced with an event having a concept paired with that of the event in the searched phenomenon by using the pair information. 6. The inference device according to claim 2, wherein the inferring unit changes the subject of the phenomenon identified by the identifying unit to another subject, and infers an effect when the subject of the phenomenon is changed, by using structural information that indicates conceptual structures among the subjects. 7. The inference device according to claim 1, wherein the identifying unit identifies another phenomenon having a causal relation with the identified effect, based on trace information that indicates at least one of whether an action of the user exerts an influence on the effect, and an extent of the influence. 8. An inference method that is performed by an inference device, the method comprising: identifying a set of a predetermined phenomenon, an effect having a causal relation with the predetermined phenomenon, and a polarity of the effect, from concept information in which a phenomenon, an effect having a causal relation with the phenomenon, a polarity to be an indicator of advantages and disadvantages caused by the effect to a user are associated with each other; and inferring an effect caused when the predetermined phenomenon occurs, and advantages and disadvantages caused by the effect based on the set identified at the identifying. 9. A non-transitory computer readable storage medium having stored therein an inference program causing a computer to execute a process comprising: identifying a set of a predetermined phenomenon, an effect having a causal relation with the predetermined phenomenon, and a polarity of the effect, from concept information in which a phenomenon, an effect having a causal relation with the phenomenon, a polarity to be an indicator of advantages and disadvantages caused by the effect to a user are associated with each other; and inferring an effect caused when the predetermined phenomenon occurs, and advantages and disadvantages caused by the effect based on the set identified at the identifying.