blem].
He read some fables to me. [Asked about the fables he was able to recall
only part of one, that of the fox and the crow.] He showed me the
picture of a field and wanted to know how to find a ball."
It is evident from the above samples of report that the danger of
coaching increases considerably with the age of the children concerned.
With young subjects the danger is hardly present at all; with children
of the upper-grammar grades, in the high school, and most of all in
prisons and reformatories, it must be taken into account. Alternative
tests may sometimes be used to advantage when there is evidence of
coaching on any of the regular tests. It would be desirable to have two
or three additional scales which could be used interchangeably with the
Binet-Simon.
RELIABILITY OF REPEATED TESTS. Will the same tests give consistent
results when used repeatedly with the same subject? In general we
may say that they do. Something depends, however, on the age and
intelligence of the subject and on the time interval between the
examinations.
Goddard proves that feeble-minded individuals whose intelligence has
reached its full development continue to test at exactly the same mental
age by the Binet scale, year after year. In their case, familiarity with
the tests does not in the least improve the responses. At each retesting
the responses given at previous examinations are repeated with only the
most trivial variations. Of 352 feeble-minded children tested at
Vineland, three years in succession, 109 gave absolutely no variation,
232 showed a variation of not more than two fifths of a year, while 22
gained as much as one year in the three tests. The latter, presumably,
were younger children whose intelligence was still developing.
Goddard has also tested 464 public-school children for three successive
years. Approximately half of these showed normal progress or more in
mental age, while most of the remainder showed somewhat less than normal
progress.
Bobertag's retesting of 83 normal children after an interval of
a year gave results entirely in harmony with those of Goddard.
The reapplication of the tests showed absolutely no influence of
familiarity, the correlation of the two tests being almost perfect
(.95). Those who tested "at age" in the first test had advanced, on
the average, exactly one year. Those who tested _plus_ in the first
test advanced in the twelve months about a year and a quarter, as we
should ex
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