No influence arising from practice is discoverable from this table,
and we may safely conclude that this hypothetical factor may be
disregarded, although among the experimenters on auditory time
Mehner[13] thought results gotten without a maximum of practice are
worthless, while Meumann[14] thinks that unpracticed and hence
unsophisticated subjects are most apt to give unbiased results, as
with more experience they tend to fall into ruts and exaggerate their
mistakes. The only stipulation we feel it necessary to make in this
connection is that the subject be given enough preliminary tests to
make him thoroughly familiar with the conditions of the experiment.

[13] _op. cit._, S. 558, S. 595.

[14] _op. cit._ (II.), S. 284.


2. The second group of experiments introduced the factor of a
difference between the stimulation marking the end of an interval and
that marking the beginning, in the form of a change in locality
stimulated, from one finger to the other, either on the same hand or
on the other hand. Two classes of series were given, in one of which
the change was introduced in the standard interval, and in the other
class in the compared interval.

In the first of these experiments, which are typical of the whole
group, both of the subject's hands were employed, and a tapping
instrument was arranged above the middle finger of each, as above the
one hand in the preceding experiment, the distance between middle
fingers being fifteen inches. The taps were given either two on the
right hand and the third on the left, or one on the right and the