1. An information processing apparatus, including one or more hardware elements, comprising: referring means for referring to a table in which a characteristic of each piece of first information is expressed as a distribution of model parameters in a plurality of semantic classes, in units of pieces of the first information; obtaining means for obtaining second information to be searched for; calculating means for calculating similarities between the second information and the respective pieces of the first information; first reading means for reading the pieces of the first information from the table in descending order of the similarity; extracting means for extracting the semantic classes of the first information read by the first reading means; and second reading means for reading the pieces of the first information from the table in descending order of model parameter in the semantic classes extracted by the extracting means; and updating means for updating a second table by determining whether a word is registered and incrementing an occurrence number associated with the word and associated with a sentence by one, wherein, after when data processing is complete, the second table is utilized in calculating the model parameters, wherein the first information read by the first reading means is recommended information that is recommended to a user as information related to the second information, and wherein the first information read by the second reading means is information provided to the user as a recommendation reason indicating which of the plurality of semantic classes is a reason the recommended information is recommended, and wherein the recommendation reason is one of the plurality of semantic classes that is scored as a highest value of similarity between the recommended information and obtained second information when a value for each of the plurality of semantic classes for the recommended information is compared with a value for each of the plurality of semantic classes for the obtained second information.
1. An information processing apparatus, including one or more hardware elements, comprising: referring means for referring to a table in which a characteristic of each piece of first information is expressed as a distribution of model parameters in a plurality of semantic classes, in units of pieces of the first information; obtaining means for obtaining second information to be searched for; calculating means for calculating similarities between the second information and the respective pieces of the first information; first reading means for reading the pieces of the first information from the table in descending order of the similarity; extracting means for extracting the semantic classes of the first information read by the first reading means; and second reading means for reading the pieces of the first information from the table in descending order of model parameter in the semantic classes extracted by the extracting means; and updating means for updating a second table by determining whether a word is registered and incrementing an occurrence number associated with the word and associated with a sentence by one, wherein, after when data processing is complete, the second table is utilized in calculating the model parameters, wherein the first information read by the first reading means is recommended information that is recommended to a user as information related to the second information, and wherein the first information read by the second reading means is information provided to the user as a recommendation reason indicating which of the plurality of semantic classes is a reason the recommended information is recommended, and wherein the recommendation reason is one of the plurality of semantic classes that is scored as a highest value of similarity between the recommended information and obtained second information when a value for each of the plurality of semantic classes for the recommended information is compared with a value for each of the plurality of semantic classes for the obtained second information. 2. The information processing apparatus according to claim 1 , wherein the extracting means extracts the semantic classes in descending order of model parameter of the first information read by the first reading means; and wherein the second reading means reads the pieces of the first information from the table in descending order of model parameter in the semantic classes extracted by the extracting means.