Finally, it appeared that the probable error of the time measurements was somewhat larger than that of the repetitions. This relation is quite intelligible in the light of the explanations given above. In the case of the time measurements the larger values, which naturally occurred with the more difficult series, were relatively somewhat greater than in the case of the number of repetitions, because relatively they were for the most part lengthened by the hesitations; conversely, the smaller times were necessarily somewhat smaller relatively than the number of repetitions, because in general they corresponded to the easier series. The distribution of the values in the case of the times is therefore greater than that of the values in the case of the repetitions.
The differences between the two methods of reckoning are, as is readily seen, sufficiently large to lead to different results in the case of investigations seeking a high degree of exactness. That is not the case with the results as yet obtained; it is therefore immaterial whether the number of seconds is used or that of the repetitions.
Decision cannot be given a priori as to which method of measurement is more correct—i.e., is the more adequate measure of the mental work expended. It can be said that the impressions are due entirely to the repetitions, they are the thing that counts; it can be said that a hesitating repetition is just as good as a simple fluent reproduction of the line, and that both are to be counted equally. But on the other hand it may be doubted that the moments of recollection are merely a loss. In any case a certain display of energy takes place in them: on the one hand, a very rapid additional recollection of the immediately preceding words occurs, a new start, so to speak, to get over the period of hesitation; on the other hand, there is heightened attention to the passages following. If with this, as is probable, a firmer memorisation of the series takes place, then these moments have a claim upon consideration which can only be given to them through the measurement of the times.
Only when a considerable difference in the results of the two kinds of tabulation appears will it be possible to give one the preference over the other. That one will then be chosen which gives the simpler formulation of the result in question.
