In connection with these tests of ability in addition, a few additional words should be said to make somewhat clearer the differences between educational tests and tests of intelligence. There is, of course, no sharp line to be drawn between these two types of tests. Mentimeter No. 10b may be classified very certainly as an educational test because it involves primarily the element of speed in simple additions which is not an accurate index of intellectual capacity but depends almost altogether upon specific drill. Improvement in ability to make a score in Mentimeter No. 10a will come much more slowly than in the case of the speed test in addition. Before a child can make progress sufficient to carry him from problem 5 to problem 6 in Mentimeter 10a, he must be instructed in the mysteries of adding zero to the sum of two other numbers. Before he can make progress from problem 6 to problem 7 he must learn to put down the 2 under the right-hand column of figures and carry the 1 to the next column and add it with the digits printed there. Each additional problem that he solves involves some new elements of arithmetic knowledge which can be learned only by careful study and one at a time. In the speed test a larger score does not indicate ability to do anything more difficult or to understand anything more complicated, but merely more rapid doing of the things which are already fully understood. In the other test, however, a larger score indicates greater comprehension of more difficult situations and therefore an intellectual capacity which is of greater magnitude. The primary purpose of the Mentimeter tests is to measure intellectual capacity rather than school training. For this reason very few tests which may be classified as primarily educational have been included. Where they have been inserted, they have been arranged to measure the ability of the person to do more difficult tasks rather than his ability to do simple tasks more rapidly. MENTIMETER NO. 11 MEMORY FOR NUMBERS _Character of the Test._ This test is planned as an individual examination to be given to any candidate who understands the English language. The test is borrowed directly from the Binet series and was used as a group test in the first form of the Alpha examination in the United States Army. The usefulness of this test is probably limited to the selection of candidates for very simple mechanical operations and to the classification of pupils in the schoolroom. It might be employed as one of a series of tests in the selection of telephone operators, but its use in such a case is probably more obvious than practical. _Directions for Giving the Test._