Perhaps the best way to learn the method will be to begin by studying the book through, in order to gain a general acquaintance with the tests; then, if possible, to observe a few examinations; and finally to take up the procedure for detailed study in connection with practice testing. Twenty or thirty tests, made with constant reference to the procedure as described in Part II, should be sufficient to prepare the teacher or physician to make profitable use of the scale. The Stanford revision of the scale is the result of a number of investigations, made possible by the coöperation of the author's graduate students. Grateful acknowledgment is especially due to Professor H. G. Childs, Miss Grace Lyman, Dr. George Ordahl, Dr. Louise Ellison Ordahl, Miss Neva Galbreath, Mr. Wilford Talbert, Mr. J. Harold Williams, and Mr. Herbert E. Knollin. Without their assistance this book could not have been written. STANFORD UNIVERSITY, _April, 1916_. CONTENTS PART I. PROBLEMS AND RESULTS CHAPTER I THE USES OF INTELLIGENCE TESTS 3 Intelligence tests of retarded school children. Intelligence tests of the feeble-minded. Intelligence tests of delinquents. Intelligence tests of superior children. Intelligence tests as a basis for grading. Intelligence tests for vocational fitness. Other uses of intelligence tests. CHAPTER II SOURCES OF ERROR IN JUDGING INTELLIGENCE 22 Are intelligence tests superfluous? The necessity of standards. The intelligence of retarded children usually overestimated. The intelligence of superior children usually underestimated. Other fallacies in the estimation of intelligence. Binet's questionnaire on teachers' methods of judging intelligence. Binet's experiment on how teachers test intelligence. CHAPTER III DESCRIPTION OF THE BINET-SIMON METHOD 36 Essential nature of the scale. How the scale was derived. List of tests. How the scale is used. Special characteristics of the Binet-Simon method. The use of age standards. The kind of mental functions brought into play. Binet would test "general intelligence." Binet's conception of general intelligence. Other conceptions of intelligence. Guiding principles in choice and arrangement of tests. Some avowed limitations of the Binet tests. CHAPTER IV NATURE OF THE STANFORD REVISION AND EXTENSION 51 Sources of data. Method of arriving at a revision. List of tests in the Stanford revision and extension. Summary of changes. Effects of the revision on the mental ages secured. CHAPTER V ANALYSIS OF ONE THOUSAND INTELLIGENCE QUOTIENTS 65