only 9 times, it was surely much easier to make the decision than when
the predominant letter appeared only 15 times and the other three each
11 times. The easier the right decision, the graver the mistake. Of
course the valuation of these mistakes must be rather arbitrary. We
decided to value as 4 every mistake in these cards on which the
predominant letter appears 21 times; as 3, a mistake in the 18 letter
cards; as 2, a mistake in the 16 letter cards; and as 1, a mistake in
the most difficult ones, the 15 letter cards. If the mistakes are
calculated on this basis and are added together, a sum below 5 may
indicate a very safe and perfectly reliable ability for decision; 5 to
12, satisfactory; 12 to 20, uncertain; and over 20, very poor. In
order to take account of both factors, time and mistakes, we multiply
the sum of the calculated mistakes by the number of seconds. If the
product of these two figures is less than 400, it may be taken as a
sign of perfect reliability in making very quick, correct decisions,
in complex life situations; 400 to 1000 indicates the limits between
which the ability for such decisions may be considered as normal and
very satisfactory; 1000 to 2000, not good but still adequate; 2000 to
3000, unreliable, and over 3000, practically absent. It is clear that
the real proof of the value of this method cannot be offered. This is
just the reason why we selected this illustration as an example of the
particular difficulty. Wrong decisions, that is, cases in which the
man on the bridge waits too long before he makes his decision and thus
causes a collision of ships by his delay, or in which he rushes
blindly to a decision which he himself would have condemned after
quiet deliberation, are rare. It would be impossible to group such
men together for the purpose of the experiment and to compare their
results with those of model captains, the more as experience has shown
that an officer may have a stainless record for many years and yet may
finally make a wrong decision which shows his faulty disposition. The
test of the method must therefore be a somewhat indirect one. My aim
was to compare the results of the experiments with the experiences of
the various individuals which they themselves reported concerning
their decisions in unexpected complicated situations, and moreover
with the judgments of their friends whom I asked to describe what they
would expect from the subjects under such conditions. The p