This chapter proposes the direct observation of human behavior. It deals with what men say and do on the ordinary occasions of ordinary life. The classification of the elements of behavior is old and crude, both. The concepts, sentiment, activity, and interaction, are close to commonsense ideas. There is a common element, and it seems to be some notion of sheer interaction between persons, apart from the particular activities in which they interact. Laymen and professional psychologists call the internal states of the human body by various names: drives, emotions, feelings, affective states, sentiments, attitudes. Science is perfectly ready to take leave of common sense, but only for a clear and present gain. Under the element of sentiment, several different kinds of studies can and have been made. Perhaps the best-known ones are carried on by the public opinion pollsters and attitude scalers using questionnaires they get people to answer.