It is to be noted that, taken literally, the description of the American Association is not in terms of the Binet scale, but of the mental development of a normal child of twelve years, although the framers of the resolution undoubtedly had the Binet scale of mental ages in mind. It was soon found that the tests for the older ages in the Binet 1908 scale were too difficult for the places assigned them. This is certainly true with the tests for twelve years and probably with those for eleven. This evidence is assembled in Table IV. The combined results should be used only with great caution since the methods of the investigators differed in detail and the groups were differently chosen. In the groups of children which Bobertag and Bloch and Preiss tested, there had been eliminated some of those who were backward in school, while Goddard's group did not include the best 12-year-olds. TABLE IV. RESULTS WITH THE BINET TESTS FOR MENTAL AGES XI AND XII (_1908 Series_) ───────────────┬─────────────┬─────────────┬─────────────────────────── │No. of Cases │ Pass tests │ Pass tests XI or better │ │XII or better│ ───────────────┼─────────────┼─────────────┼─────────────────────────── │ Life-Age │ Life-Age │ Life-Ages ───────────────┼─────────────┼─────────────┼─────────────┬───────────── Investigators │ 12 11 │ 12 │ 11 │ 12 │ No. No. │ No. % │ No. % │ No. % ───────────────┼─────────────┼─────────────┼─────────────┼───────────── Binet and Simon│ │ │ │ (School in poor│ │ │ │ quarter) │ │ │ │ 1908 study │ 11 │ 2 18 │ │ 7 64 │ 20 │ │ 13 65 │ 1911 study │ 23 │ │ │15[13] 65 ───────────────┼─────────────┼─────────────┼─────────────┼───────────── Bloch and │ 21 │ 21 100 │ │ 21 100 Preiss │ │ │ │ (Only pupils up│ 15 │ │ 13 87 │ to grade) │ │ │ │ ───────────────┼─────────────┼─────────────┼─────────────┼───────────── Bobertag │ 33 │ 19 57 │ │ 29 88 (Pupils │ 34 │ │ 18 53 │ averaged │ │ │ │ satisfactory) │ │ │ │ ───────────────┼─────────────┼─────────────┼─────────────┼───────────── Dougherty │ 46 │ 9 20 │ │ 36 78 (Includes 8th │ 44 │ │ 22 50 │ grade) │ │ │ │