=Method of Marking.=--The examiner should have a large sheet of paper or a note-book with the names of the tests written in column at the left-hand side. Opposite each in a second column he should enter a sign indicating his judgment. Binet recommends the use of the following signs: + ! excellent, + pass, + ? almost a pass, ? doubtful, 0 silence,-- ? almost a failure, -- a failure, -- ! a bad failure. Later this record should be supplemented from the notes taken by the secretary, also by information regarding the child's personal history, and by comments on his behaviour during the examination. The mental age assigned to him is determined in this way: one finds the age-level at which he passes all the tests, and adds a year for every five tests that he passes above that level. Thus, if a child of seven passes all the tests for seven years, three of those for eight, and two of those for nine, he has a mental age of eight years. Binet allows the use of fractions, one-fifth of a year for every test passed, but he admits that this gives an appearance of a degree of exactitude which is probably not attained. Should a child's mental age show a retardation of three years as compared with his chronological age, and should there be no evident explanation of this, such as ill-health, neglect of school attendance, etc., he is reckoned as deficient mentally. Binet's scale has been criticised from various points of view. Generally speaking, it seems to be found too easy at the lower end and too difficult at the higher end. It seems certain that some of the tests have not yet found their proper level, or, indeed, that the proper level may vary from country to country, from school to school, and from one social rank to another. Thus, the writer has found that practically all the five-year-old children present in a certain school during the past two or three years are able to pass the colour test assigned by Binet to seven years of age. These children, however, probably belong to a higher social class than the five-year-olds tested by Binet. An examiner very quickly learns which of the tests beyond his age it is advisable to put to the particular child he is dealing with, and owing to the method of marking it does not matter much if one or two tests are misplaced with reference to a particular group of children. The important thing is that there is a general consensus of opinion on the part of those who have tried the scale as to its value as a mental probe and register of mental attainment. Revisions and elaborations of it have already been published,[B] but in view of its simplicity and brevity, and the valuable analytical work of which it has proved itself capable, the 1911 form will probably remain a standard for at least some years to come. For the complete series of tests the examiner will require the following material in addition to the diagrams: Three suitable pictures. Key, penny, knife. IV. 2. Weights. V. 1 and X. 1. Drawing of square. V. 2.