Book excerpt: "In the main, the method of the book is the method that has been called that of the "participant observer." The book should be used by the student, therefore, as a sort of laboratory manual, its generalizations to be tested so far as possible by the observation of social groups with which the student has had experience. Illustrative material will also be found, however, in written history, in anthropological books, and in works in sociology, especially in my elementary text, Sociology and Modern Social Problems. Such qualitative analysis of the determinants in group behavior is necessary before quantitative analysis can be fruitfully undertaken"--Préface. (PsycINFO Database Record (c) 2015 APA, all rights reserved).