188 



MEMOIRS NATIONAL ACADEMY OF SCIENCES. 



[Vol. XV, 



Test 7, the digit symbol test. 



Materials. See page 277. 



Directions. — The part of the first row marked sample is used for demonstration. Examiner says, " You see these 

 numbers and the little mark below each number (pointing to the row at the top of the page). Now, I want you to put in each 

 one of these squares (pointing to the empty squares in the three rows) the little mark that ought to go there, like this: 

 Below 2 put this little mark (beginning at 2 in the sample); below 1, this; below 3. this;" etc. After doing five of the 

 samples examiner pauses and asks, "Now, what should I put heret " (indicating the next empty square). If subject 

 answers correctly, examiner finishes the samples himself; if subject fails, examiner tells him and repeats the ques- 

 tion with the next sample. After finishing the demonstration, examiner says: "Now, you begin here and fill as many 

 squares as you can before I call time. " 



Time, 2 minutes. 



Scoring. — The score is the number of squares filled correctly in the time limit. Maximum raw score, G7 points. 



Test S, the maze. 

 Materials. — The four mazes (a), (b), (c), and (d) on page 278 and demonstration maze on page 277. 

 Directions. — Examiner shows subject demonstration maze and says, " You see these lines. Now I am going to 

 begin here at S and mark with my pencil the shortest way out without crossing any lines. Watch carefully. " Examiner 

 places sheet so that the bottom of the maze is toward subject, and traces the 'vay out, calling attention to the possibility 

 of taking the wrong path at one or two of the critical points. Examiner says, You see, if I should go this way, it would 

 not be the shortest way out. I should have to turn back." Examiner then preseu ' test maze (a) on page 278 and says: 

 "Now, with your pencil begin at S and mark the shortest way out as quickly as you can. Do not cross any lines and do 

 not turn back unless you have to. Ready — Go ahead. " 



If subject crosses a line, not through carelessness, examiner says, " You have crossed a line here. You see it is 

 not an open space. Begin here (indicating a point on the pencil mark just before it crossed the line) and see if you can 

 find a path out without crossing any lines. " In scoring, subject is penalized 1 point for each line crossed as above. 



Mazes (6), (c), and (d) should be presented in the same way as (a) except that no further demonstration is allowed. 

 Time limit for each maze, 2 minutes. If the score on (o) and (b) is 0, the test may be discontinued. 



Scoring. — Time is recorded in seconds from start signal to successful exit. If this occurs within the time limit, 

 credit for time is given for each maze as follows: 



Time. Credit. 



0-20 3 



21-40 2 



41-70 1 



71-120 



Fig. L Key mazes. 



