Reading of previous studies has continued, with emphasis being placed upon a review and appraisal of the methodological procedures utilized in earlier investigations. A great many experimental investigations of level of aspiration have been conducted since attention was first drawn to this field by the work of two of Lewin's students, Hoppe and Dembo, in Germany in 1931, followed by Jerome Frank in America in 1935. In reading the literature, one is impressed with the great variety of different experimental procedures that have been utilized in level of aspiration studies. In some instances the nature of the task, the instructions to the subject, and other procedural details differ so much from one study to another that it is quite evident that appreciably different patterns of behavior are elicited by the test procedures. In the present review of previous studies, therefore, it was felt that it would be valuable to summarize in considerable detail the variety of different experimental procedures that have been utilized by various investigators.