EMPLOYMENT PSYCHOLOGY
of difficulty of recording and scoring and the necessary constant
 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 handwriting,
 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 diameter,
 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 distinguish
 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 unaware
 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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