the detailed records for each trial, tables have been constructed which
offer in brief space the essential data for every trial in connection
with a given problem.

Table 1 contains the results for Skirrl in problem 1. It is constructed
as follows: the date of a series of trials appears in the first vertical
column; the numbers (and number) of the trials for the series or date
appear in column 2; the following ten columns present respectively the
results of the trials for each of the ten settings. Each number, in
these results, designates a box entered. At the extreme right of the
table are three columns which indicate, first, the number of trials in
which the right box was chosen first, column headed R; and second, the
number of trials in which at least one incorrect choice occurred, column
headed W. In the last column, the daily ratio of these first choices
appears.

Taking the first line of table 1 below the explanatory headings, we note
on April 19 ten trials, numbered 1 to 10, were given to Skirrl. In trial
1, with setting 1, he chose correctly the first time, and the record is
therefore simply 1. In trial 2, setting 2, he incorrectly chose box 9,
the first time. At his next opportunity, he chose box 8, which was the
right one. The record therefore reads 9.8. In trial 3, setting 3, he
chose incorrectly twice before finally selecting the right box. The
record reads 6.7.3, and so on throughout the ten trials which constitute
a series. The summary for this series indicates three right and seven
wrong first choices, that is, three cases in which the right box was
entered first. The ratio of right to wrong first choices is therefore 1
to 2.33. Since the total number of doors open in the ten settings is
thirty-five, and since in each of the ten settings one door is
describable as the right door, the probable ratio, apart from the