1. A hardware configuration of an information processing device comprising a microprocessor configured to execute evaluation prediction functions, the microprocessor comprising: an estimating section configured to define a plurality of first latent vectors indicating features latently possessed by a plurality of first items, respectively, a plurality of second latent vectors indicating features latently possessed by a plurality of second items, respectively, evaluation values corresponding to respective combinations of said first items and said second items and expressed by inner products of said first latent vectors and said second latent vectors, a plurality of first feature vectors indicating known features possessed by the plurality of said first items, a plurality of second feature vectors indicating known features possessed by the plurality of said second items, a first projection matrix for projecting said first feature vectors into a space of said first latent vectors, and a second projection matrix for projecting said second feature vectors into a space of said second latent vectors, express said first latent vectors by a normal distribution having projection values of said first feature vectors projected by said first projection matrix as expected values, and express said second latent vectors by a normal distribution having projection values of said second feature vectors projected by said second projection matrix as expected values, and perform Bayesian estimation with said first feature vectors, said second feature vectors, and a known said evaluation value as learning data, and calculate a posterior distribution of a parameter group including said first latent vectors, said second latent vectors, said first projection matrix, and said second projection matrix; and a predicting section configured to calculate a distribution of an unknown said evaluation value on a basis of the posterior distribution of said parameter group and calculate an expected value of said unknown evaluation value on the basis of the posterior distribution of said parameter group.