This paper is a review of the current research on mathematical psychology in the field of learning. The first part of the article defines mathematical learning theory, the characteristics of the mathematical models, its history and applicability. The second part analyses in detail Estes' statistical approah or Stimulus Sampling Theory, This theory is based in the notion that the subject's response is determined by a sampling process defined on a hypothetical population of stimulus elements. A critical evaluation of this theory is attempted.