SCATTERING OF SUCCESSES. It is sometimes a source of concern to the untrained examiner that the successes and failures should be scattered over quite an extensive range of years. Why, it may be asked, should not a child who has 10-year intelligence answer correctly all the tests up to and including group X, and fail on all the tests beyond? There are two reasons why such is almost never the case. In the first place, the intelligence of an individual is ordinarily not even. There are many different kinds of intelligence, and in some of these the subject is better endowed than in others. A second reason lies in the fact that no test can be purely and simply a test of native intelligence. Given a certain degree of intelligence, accidents of experience and training bring it about that this intelligence will work more successfully with some kinds of material than with others. For both of these reasons there results a scattering of successes and failures over three or four years. The subject fails first in one or two tests of a group, then in two or three tests of the following group, the number of failures increasing until there are no successes at all. Success "tapers off" from 100 per cent to 0. Once in a great while a child fails on several of the tests of a given year and succeeds with a majority of those in the next higher year. This is only an extreme instance of uneven intelligence or of specialized experience, and does not necessarily reflect upon the reliability of the tests for children in general. The method of calculation given above strikes a kind of average and gives the general level of intelligence, which is essentially the thing we want to know. SUPPLEMENTARY CONSIDERATIONS. It would be a mistake to suppose that any set of mental tests could be devised which would give us complete information about a child's native intelligence. There are no tests which are absolutely pure tests of intelligence. All are influenced to a greater or less degree also by training and by social environment. For this reason, all the ascertainable facts bearing on such influences should be added to the record of the mental examination, and should be given due weight in reaching a final conclusion as to the level of intelligence. The following supplementary information should be gathered, when possible:-- 1. Social status (very superior, superior, average, inferior, or very inferior). 2. The teacher's estimate of the child's intelligence (very superior, superior, average, inferior, or very inferior). 3. School opportunities, including years of attendance, regularity, retardation or acceleration, etc. 4. Quality of school work (very superior, superior, average, inferior, or very inferior). 5. Physical handicaps, if any (adenoids, diseased tonsils, partial deafness, imperfect vision, malnutrition, etc.).