The present manual interprets the basic mathematical methods offered by the mathematical theory and widely put into practice in modern psychologypedagogical researches. The basic concepts of probability theory are stated and concrete mathematical methods of data processing are described. A reader would find general recommendations about statistical software packages usage. The statement is conducted practically without strict mathematical proofs, but with detailed discussions, explanations and illustrations. Essence and applicability borders for specific statistical analysis methods are explained. The book is intended for students and teachers of higher schools.