At the beginning of the two-test training I thought
it possible that the animals might acquire a perfect
habit with only a few more days’ training than
is required by the ten-test method. This did not
prove to be the case, for at the end of the twentieth
day (after forty tests in all) the average number
of mistakes, as Table 42 shows, was 3.2 for the males
and 3.0 for the females. Up to this time there
had been clear evidence of the formation of a habit
of discriminating white from black, but, on the other
hand, the method had proved very unsatisfactory because
the first test each day usually appeared to be of
very different value from the second. On account
of the imminent danger of the interruption of the experiment
by the rapid spread of an epidemic among my mice,
I decided to increase the number of tests in each
series to five in order to complete the experiment
if possible before the disease could destroy the animals.
On the twenty-first day and thereafter, five-test
series were given instead of two-test. Unfortunately
I was able to complete the experiment up to the point
of thirty successive correct tests with only six of
the ten individuals whose numbers appear at the top
of Table 42. That the results of this table are
reliable, despite the fact that some of the individuals
had to be taken out of the experiment on account of
bad condition, is indicated by the fact that all the
mice continued to do their best to discriminate so
long as they were used. Possibly the habit would
have been acquired a little more quickly by some of
the individuals had they been stronger and more active.
It should be explained at this point that the results
in all the efficiency-of-training tables of this chapter
are arranged, as in the previous white-black discrimination
tables, in tens, that is, each figure in the tables
indicates the number of errors in a series of ten tests.
In all cases A and B mark preliminary
series of tests which were given at the rate of ten
tests per series. The numbers in the first column
of these tables designate groups of ten tests each,
and not necessarily daily series. In Table 42,
for example, 1 includes the results of the first five
days of training, 2, of the next five days, and so
on. The table shows that No. 80 made seven wrong
choices in the first five series of two tests each.
This method of grouping results serves to make the
data for the different methods directly comparable,
and at the same time it saves space at the sacrifice
of very little valuable information concerning the
nature of the daily results. It is to be noted,
with emphasis, that the two-five tests per day training
established a perfect habit after four weeks of training.
This method is therefore costly of the experimenter’s
time.
TABLE 42
EFFICIENCY OF TRAINING. WHITE-BLACK TESTS AT
THE RATE
OF 2 OR 5 PER DAY
MALES FEMALES
SETS 80 82 84 86 88 AV. 73 79 83
85 89 AV.
OF 10
Copyrights
The Dancing Mouse from Project Gutenberg. Public domain.
