6. Success in alternative tests may not be substituted for failure in one of the regular tests. Ordinarily the alternatives should be omitted. They have been included in the scale chiefly as a convenience in case materials are lacking for any of the regular tests, or in case any of the latter should be deemed for some special reason unsuitable. The ball and field test, for example, is often rendered unsuitable by coaching, and one of the alternates should always be substituted for the vocabulary test in the case of subjects whose mother tongue is other than English. Other substitutions or omissions are necessary in the case of subjects who are illiterate. 7. Care should be taken to ascertain the correct age. This is often misstated both by young normal children and by defectives. The age should be recorded in years _and months_. 8. In ordinary calculation of the intelligence quotient without any mechanical aid (as slide rule, calculating chart, or table), both age and mental age should be reduced to months before dividing. 9. To avoid the danger of large error it is absolutely essential that the adding of credits to secure mental age and the dividing of mental age by chronological age to secure the intelligence quotient be performed twice. 10. Finally, in calculating the intelligence quotient of subjects who are more than sixteen years old, the chronological age should be counted as sixteen. It is possible, as certain army data suggest, that a lower age than sixteen should have been taken, but until the matter has been more thoroughly investigated by the use of unselected adult subjects the age sixteen will continue to be used in the Stanford Revision. DIRECTIONS: THE TESTS[2] [Footnote 2: Detailed directions for administering Stanford-Binet Scale and for scoring are available in Terman's _The Measurement of Intelligence_. (Riverside Textbooks in Education.) Houghton Mifflin Company.] Year III 1. _Pointing to Parts of Body_ Say, "Show me your nose." "Put your finger on your nose." If two or three repetitions of instructions bring no response, say, "Is this (pointing to chin) your nose?" "No?" "Then where is your nose?" Same for eyes, mouth, and hair. Credit if correct part is indicated (in any way) three times out of four. 2. _Naming Familiar Objects_ Show S., one at a time, key (not Yale), penny (not new), closed knife, watch, pencil. Say each time, "What is this?" or, "Tell me what this is." Credit if three responses out of five are correct. 3. _Pictures--Enumeration_ Say, "Now I am going to show you a pretty picture." Show picture (_a_) and say, "Tell me what you see in this picture," or, "Look at the picture and tell me everything you can see in it." If no response, "Show me the ----." "That is fine: now tell me everything you see in the picture." If necessary ask, "And what else?" Same for pictures (_b_) and (_c_).