VIII
PSYCHOLOGICAL TESTS
(Concluded)
Performance tests. Technique of test construction. Order of items. Length
of test. Time limits. Directions and fore-exercise. Directions for scoring
the test. Omnibus tests. Alternative forms. Arrangement in series.
Performance tests require something other than a language
response. They are usually administered as individual tests,
although there are many group performance tests. Their
best usefulness is to measure manual skills, mechanical
aptitudes, and personality and character traits. They are
indispensable in testing the intelligence of illiterate or
foreign applicants.
A performance test may consist of merely one step or
standard task, the score being in terms of the time required
to complete this task; or it may consist of a number of units,
the score being either in terms of time required, number of
units completed within the stated time, or quality of product,
measured by comparison with typical samples arranged in
a scale of excellence.
If apparatus is used, it should be of sturdy construction,
and easily replaceable. It is advisable to have a duplicate
set for emergencies, and in any event the specifications for
the apparatus should be so explicit that any investigator
can duplicate it with entire certainty that he is reproducing
the standard conditions. To this end the use of rare and
unusual materials is deprecated.
The apparatus should if possible have automatic devices
for recording performance.
Laboratory manuals for experiments in psychology are a

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