Patent ID: 8924405

Claim:
An information processing apparatus comprising: at least one processor; a history information obtaining unit to obtain, by the at least one processor, history information about a predetermined operation, the history information including unique identification information and time information at which the predetermined operation is performed by a classification subject associated with the unique identification information or time information at which the predetermined operation is performed on the classification subject, the unique identification information and the time information being associated with each other; and a reference value determining unit to calculate, by the at least one processor, operation number information based at least in part on the obtained history information, the operation number information including a number of operations performed by a first single classification subject within a predetermined period, wherein the first single classification subject comprises a user, or a number of operations performed on a second single classification subject within the predetermined period, wherein the second single classification subject comprises content, the operation number information further including a number of classification subjects having a same number of operations, the number of operations and the number of classification subjects being associated with each other, the reference value determining unit determining a reference value based at least in part on the operation number information, the reference value being the number of operations serving as at least a partial basis for classifying the classification subjects into two classes, wherein the reference value determining unit further includes: a parameter setting unit to set a parameter used for determining the reference value; a function calculation unit to calculate, based at least in part on the history information, a function represented by a product of the number of operations and a ratio of a number of classification subjects having the number of operations to a total number of classification subjects; a histogram calculation unit to classify the number of operations included in the operation number information into a plurality of groups based at least in part on a parameter representing the base of a logarithm set by the parameter setting unit, and to calculate a histogram represented by a summation of values of the function calculated using the number of operations belonging to each group; a group detection unit to detect the group yielding a maximum value of the histogram; and a reference value calculation unit to calculate the reference value based at least in part on the detected group.