These norms differ somewhat from those derived from the grade norms by translation of grade into average age for the grade. This is because the norm for a grade is the average score for a grade. Hence the norm of age 10 obtained in this way is the average score obtained by a grade whose average age is 10. Then the data used to obtain this average are made up of diverse ages, all of one grade, instead of all of one age and diverse grades. Even then, we would have only an average score of an age which approximates what we want, but is not as reliable to use as average age for a score. A METHOD OF SURVEY OF READING, LANGUAGE, AND ARITHMETIC The following procedure was employed in the experiment. The experiment was carried out in the public school at Garden City. Two hundred children were given the tests. The instructions, shown below, were followed in November, 1919, and in November, 1918; in June, 1919, and in June, 1920, with the exception that no arithmetic test was used in November, 1918, and June, 1919. The Binet tests were given by the author; all of the others were given either by the author or the principal who was careful not to deviate from the directions in any way. In June of both years the author gave instructions for a test in one room, and then left the teacher in charge and went on to the next. This could be done in June of each year as the teachers were then fully acquainted with the experiment and their coöperation was assured. DIRECTIONS I. Administer and score the following tests according to standard instructions. Give all tests to grades 3 and above. Woody-McCall Mixed Fundamentals in Arithmetic Thorndike Reading Scale Alpha 2 Thorndike Visual Vocabulary Scale, A2 Kelley-Trabue Completion Exercises in Language Stanford-Binet Tests (given by the author) II. Translate the scores into year-month indices of maturity by means of the following table. (Use Mental Age for the Binet.) Assume rectilinear development, that is, that the amount of score which equals the development of one month is the same as the amount of score which equals the development of any other month. Then interpolation and extension are allowable. Use the table in this way: Find in the table the score made by a child (for instance in the Woody-McCall); find the age to which it corresponds, then call this age the Arithmetic Age of the child. For instance, if the score in Woody-McCall is 20, his Arithmetic Age is about halfway between 10 and 11 or 10 years 6 months.