From the review of prof. zw. dr. hab. Stanislaw PalkaThe work of Janusz Gnitecki concerns a topic of fundamental importance for the practice of scientific research in pedagogy, although publications orparts of books on pedagogical research methods can be found in the Polish literature, however, there is no book that contains an orderly lecture on this topic, the previous publications of other authors capture the subject either in a cursory way, or inconsistent with other studies, which indicates a lack of uniformity of approach to the problem of methods [...]. Janusz Gnitecki's book can bring the necessary order in the field of methodological literature.