THE METHOD OF AGE GRADATION 35 



answers are more, others less satisfactory to him: 

 rather must he maintain an attitude of uniform and 

 quiet friendliness. The recorder should not confine 

 himself to the mere noting of plus and minus signs 

 to show the net outcome of each test, but should also 

 note down as fully as possible what the subject says 

 and also such features of his behavior and attitude 

 toward the tests as are worth noting. This is neces- 

 sary both because it is often impossible to decide 

 whether to credit a test 'plus' or l minus' until later 

 on, after quiet consideration (and the material must 

 be available for that) and also because it should 

 make possible a qualitative analysis of the examinee. 

 The individual subject ought, of course, to be 

 tested not only with the tests of his age, but also 

 with a considerable part of the whole series on ac- 

 count of the area of scattered distribution to be dis- 

 cussed in a moment. The examiner should begin 

 with tests that are neither too easy nor too difficult, 

 avoid monotony and introduce short pauses if fatigue 

 becomes noticeable. The testing of a single indi- 

 vidual takes, for normals 20 to 30 minutes, accord- 

 ing to age and circumstances, for abnormals from 

 one-half to three-quarters of an hour, on account of 

 the slower response. 



In mass experiments there is a source of difficulty in the possi- 

 bility of communication between those already tested and those 

 to be tested. It is true that the danger of such a 'psychic infec- 

 tion' is not very great, on account of the peculiar character of the 

 material used for the testing; nevertheless, one should avoid, as 

 far as may be, the possibility of any spreading of information. 

 Thus, for instance, it is not advisable to test the pupils of one 

 class on several days in succession. If it is desired to examine a 

 rather large number of children that belong in the same group, the 

 plan followed at Breslau seems useful : four experimenters (with 

 their clerks), all of whom had been trained to conduct the tests 



