EMPLOYMENT PSYCHOLOGY 
of difficulty of recording and scoring and the necessary con- 
stant supervision by the examiner. 
Where written responses are required, the amount of 
writing should be reduced to a minimum not only because 
of the saving in time, but also because of sources of error 
through variations in speed of writing, illegibility of hand- 
writing, and difficulty of scoring. 
Catch questions should be avoided. 
There are conditions under which catch questions are 
necessary, but they rarely arise in industry. In wartime 
it was not uncommon to find conscripts who simulated 
color-blindness in an effort to avoid military service. A 
clever test developed in Germany meets this situation (215). 
It consists of a number of charts each composed of small 
colored dots, averaging about a quarter of an inch in diam- 
eter, printed close together. To the person with normal 
color vision, numerals formed of dots of a single color stand 
out in each chart. The color-blind person cannot distin- 
guish these numerals because their gray value is the same 
as that of the other dots. In several of the charts, however, 
the numerals have a distinct gray value and can be read 
even by color-blind persons. The malingerer who is un- 
aware of this fact is detected when he claims that he cannot 
see any numerals on these charts. 
Questions should not follow in such a sequence that one 
suggests the answer to another. 
To facilitate scoring, items should be printed so that all 
answers appear in a column near the edge of the sheet. 
Verbal tests may require either a spoken or written reply. 
Thurstone has suggested a classification of verbal test items 
according to the degree of constraint they impose on the 
response. 
A. Free response 
B. Constrained response 
1. Imposed by wording of question 
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