it by guess. That this
is not an unfair statement of the case is well shown by the following
candid confession by a psychologist who tested 200 juvenile delinquents
brought before Judge Lindsey's court:--
[35] See this volume, p. 24 _ff._
As a matter of interest I estimated the mental ages of 150 of my
subjects before testing them. In 54 of the estimates the error
was not more than one year in either direction; 70 of the
subjects were estimated too high, the average error being
2 years and 7 months; 26 of the subjects were estimated too low,
the average error being 2 years and 2 months. _These figures
would seem to imply that an estimate with nothing to support it
is wholly unreliable, more especially as many of the estimates
were four or five years wide of the mark._[36]
[36] C. S. Bluemel: "Binet Tests on 200 Delinquents," in _The Training
School Bulletin_ (1915), p. 192. (Italics inserted.)
Criticisms of the Binet method have also been frequently voiced, but
chiefly by persons who have had little experience with it or by those
whose scientific training hardly justifies an opinion. It cannot be too
strongly emphasized that eminence in law, medicine, education, or any
other profession does not of itself enable any one to pass judgment on
the validity of a psychological method.
DEPENDENCE OF THE SCALE'S RELIABILITY ON THE TRAINING OF THE EXAMINER.
On this point two radically different opinions have been urged. On the
one hand, some have insisted that the results of a test made by other
than a thoroughly trained psychologist are absolutely worthless. At the
opposite extreme are a few who seem to think that any teacher or
physician can secure perfectly valid results after a few hours'
acquaintance with the tests.
The dispute is one which cannot be settled by the assertion of opinion,
and, unfortunately, thoroughgoing investigations have not yet been made
as to the frequency and extent of errors made by untrained or partially
trained examiners. The only study of this kind which has so far been
reported is the following:--[37]
[37] Samuel C. Kohs: "The Binet Test and the Training of Teachers," in
_The Training School Bulletin_ (1914), pp. 113-17.
Dr. Kohs gives the results of tests made by 58 inexperienced teachers
who were taking a summer course in the Training School at Vineland. The
class met three times a week for instruction in the use of the Binet
scale. Du
|