Belding banner. (Belding, Mich.) 1889-1918, 1896-04-09
TRICKS OF MEMORY.
TESTS OF. THE RELIABILITY OF REC.
OBJECTION AT COLUMBIA.

/ ~ OutstlOn lnat Aento ~ tourt
Trials That Ii Not Always Easily An.
swered Correctiy-Lack of Accuracy Of
the Memory In Common Occurrences
have tried in various ways to secure a
quantitative determination OF the reliabil-
ity OF recollection and evidence and will
here report on the answers TO some ques-
lions asked the Junior class In psychology
In Columbia college In March, 1893. The
questions were answered In all or In part
by the 56 students present. Several simple
questions were first asked and the stu.
dents allowed in each case one-half minute
to consider and write the answer. They
were also requested to assign the conf
dence which they felt in the correctness Of
their answer. The first question was.
"What was the weather week ago todayg'
The answers were pretty equally distribut-
cd over all kinds OF weather which are pos
sible at the beginning Of March. or the
SO answers IS may be classed as Clear
10 rain" SNOW" stormy" 9
"cloudy'' and 8 partly stormy and partly
clear. ION the day in question 1t showed
| In the morning and cleared in the late aft
ernoon) 1t seems that an average man
with "a moderate time for reflection cannot
state much better what the weather was
week ago than what IL will be week
hence Yet this is "a question that might
naturally be asked in "a court of justice.
| An INSCRIPTIONS attorney can discredt
| the statements of a truthful witness by
| ounningly selected questions. The jury,
or at least the Judge, should know how far
| errors in recollection are normal and how
| they vary under different conditions.
When asked "What was the weather two
weeks agop' 20 students answered clear
and IS stormy" The confidence in this
case was slight, only two being sure that
| their answers were correct and eight hav-
ing some confidence, while the Others were
doubtful or did not answer at all. Three
questions were asked with n view TO learn
ing the ordinary accuracy of observation:
"Do chestnut trees or oak trees lose their
leaves the earlier in the autumn" do
horses in the field stand with head or tail
TO the wind?" "In what direction do the
seeds of an apple pointy' The questions
were all answered correctly more often
than incorrectly, but only by moderate
majority. Thus 30 students thought that
chestnut trees lose their leaves the earlier
In the autumn, and 81 were Of the opposite
opinion; "a students thought that horses
in the field stand with tails TO the wind,
and 10 thought they stand facing 1t. Thus
In only about three cases out of five will
college student answer such question
correctly.
Each class OF persons would of course
have n different index of precision. In
the present cases country boys would prob
ably do better, whereas in other directions,
IS in Judging of character, they might not
! do so well. This opens up an interesting
direction of research. Is the ordinary OBJ
servation Of men or women BETTER of stu
dents in classical or scientific courses, etc?
The degree of confidence may be noticed.
The students were sure their answers we're
correct in all "a times, and in these cases
they were in fact correct % times. They
were somewhat or quite doubtful in all 20
times, and i'm these cases were correct 81
times, scarcely more than "A majority.
Their Judgment Of their own accuracy was
therefore Of some value, and the degree Of
confidence can with advantage be taken in
ordinary testimony. But there is great
individual difference in this respect
Some observers are nearly always sure
that they are right, whereas others whose
decision is equally or more likely To be
correct are much less confident. In other
and more elaborate experiments | have
found that when an observer is entirely
doubtful, for example; as To which of two
weights is tho heavier and makes "a guess,
his guess is more likely To be right than
wrong. This opens an opportunity for
determining the part played by subcon-
scious inference in the decisions Of daily
life, rs in judging tho character from the
face.
As regards the direction i'm which the
seeds in an apple point, "a answers were
upward, - or toward stem" Is toward
center" 10 downward" and three tout
ward The reader may be left to decide
whether or not ho knows in what direction
the seeds, in fact, point, and what infor.
nation he can obtain from these answers.
Three questions were asked intended 70
determine the average accuracy in esti-
mating weight, distance and time. These
were the weight Of the textbook DANES
"Briefer Course" in psychology used by
the class, the distance between two build
ings on the college grounds and tho time
usually taken by students to walk from
the entrance door of the building to the
door of the lecture room. In these cases
there was a marked tendency to underesti-
mate weight and to overestimate time.
Length was overestimated, but to less
degree. For the magnitudes used the
average variation was about one-third Of
the weight and one-half of the distance or
time. The actual errors were larger in
the case of weight and time, but not in
the case of distance. The middle estimate
or median value, is in all cases smaller
than the average. The degree of conf
dence of the observer does not in these
cases seem to measure objective accuracy.
Science.