1. An estimating device comprising: predictive computing means configured to estimate, based on an evaluation matrix made up of an evaluation value indicating an evaluation as to each of a plurality of evaluation targets for each of a plurality of users, and an estimated expression for estimating said evaluation value by computation employing said evaluation matrix, said evaluation value of said evaluation target which has not been subjected to an evaluation by said user, and obtain a predictive evaluation value which is said estimated evaluation value; and linear combining means configured to subject a plurality of said predictive evaluations obtained by employing a plurality of said estimated expressions to linear combination by employing a linear combination coefficient, thereby obtaining a final estimation result of an evaluation as to said evaluation target which has not been subjected to said evaluation by said user.