The Relation between Memory for Words and Memory for Numbers, and the Relation between Memory over Short and Memory over Long Intervals

STOP

Early Journal Content on JSTOR, Free to Anyone in the World

This article is one of nearly 500,000 scholarly works digitized and made freely available to everyone in
the world by JSTOR.

Known as the Early Journal Content, this set of works include research articles, news, letters, and other
writings published in more than 200 of the oldest leading academic journals. The works date from the
mid-seventeenth to the early twentieth centuries.

We encourage people to read and share the Early Journal Content openly and to tell others that this
resource exists. People may post this content online or redistribute in any way for non-commercial
purposes.

Read more about Early Journal Content at http://about.jstor.org/participate-jstor/individuals/early-
journal-content .

JSTOR is a digital library of academic journals, books, and primary source objects. JSTOR helps people
discover, use, and build upon a wide range of content through a powerful research and teaching
platform, and preserves this content for future generations. JSTOR is part of ITHAKA, a not-for-profit
organization that also includes Ithaka S+R and Portico. For more information about JSTOR, please
contact support@jstor.org.

THE RELATION BETWEEN MEMORY FOR WORDS AND
MEMORY FOR NUMBERS, AND THE RELATION
BETWEEN MEMORY OVER SHORT AND MEM-
ORY OVER LONG INTERVALS.

By Edward L. Thorndike, Teachers College, Columbia University.

Measurements of mental relationships are so important and so
scanty that I venture to report certain ones in the case of memory,
although they are by no means satisfactory with respect to method.
They will not, however, be misleading to any one who bears in mind
their limitations.

The measurements are of the relations in educated adults: — (i)
between (a) the ability to remember a list of twelve words from a
single hearing, at a rate of approximately one per second, long
enough to write them immediately at the close of the reading; and
(b) the same ability in the case of a list of five three-place numbers.
There were five lists of fa) and five lists of (b) . (2) Between : (a)
and (c) the ability to remember the sixty words given in the five
tests of (a) twenty-four hours later.

No requirements were made as to the order except, of course, that
the order of the digits within each three-place number must be cor-
rect. The basis of the memory of (c) was not only the single hearing,
and the experience of writing down such words as the individual
remembered, but also the experience of scoring one's results from a
complete list given to the individual for that purpose.

(1) and (2) do not, that is, measure the relationships in general,
but the relationships as influenced by the restriction of the tests to
one half-hour in the case of (1) and (2) and the relationship as in-
fluenced by the variations in the degree of attention given to the
words in scoring results in the case of (2). Moreover, I have not
corrected the results for spurious correlation due to sex, nor for atten-
uation due to the small number of tests.

The lists used and the method of scoring were as follows: The num-
ber of individuals was 38 for relation 1 and 40 for relation 2.

The lists of words used were :

near

bell

break

out

cloud

call

false

box

sleep

lot

slate

drop

gift

cap

smile

end

wing

run

cheat

flag

eat

thought

bed

cry

lose

stone

drink

add

Pig

hit

queer

house

sing

full

nose

skip

The lists of numbers used were :
791 254 639

469

624

716

maze

cress

hob

zest

eke

slink

fob

lush

elk

bland

tweak

lilt

e

yet

shall

and

lest

how

could

though

when

let

your

since

more

579
356

746

823

264

974

435

35»

4 8 8 THORNDIKE

918 683 532

493 321 228

671 572 787

The score for one correct word was 1.

A word apparently misheard but remembered as heard (e.g., slake
for slate or amaze for maze) was scored correct. Each individual's
testimony was accepted in such cases. For each word written that
was not in the list a discount of one word was made. Such errors
are rare, making only 3 per cent, of the words written ; 50 seconds
were allowed to write out the words remembered for each list.

Each three-place number recalled exactly counted 1. Each number
of which two digits were correct and correctly placed counted .5.
30 seconds were allowed to write out the numbers for each remembered
list.

The obtained 'raw' correlation for (1) is .4% ± .1. The mixture of
the two sexes and the testing of the two traits in the same hour tend
to make this higher than the relation between the general ability to
remember word lists and the general ability to remember three-place
number lists. On the other hand, there is the attenuation due to the
variation, in both (a) and (b), of the result from five tests from the
person's true ability. I estimate that correction for all three would
result in a correlation of about .5JS. The relation between (a) and
memory of lists of 12 single digits was found to be .6, eight inde-
pendent records of each being used. Correction for attenuation raises
this to .7 — . So, until more adequate measures are made, we may
accept as the most likely fact that, in such a test of brief retention, a
variation in the content from words to numbers reduces the correla-
tion from 1 to about %. Even if the reduction should prove to be to
only %, the fact would still be very strong evidence of the depend-
ence of efficiency of memory upon content and of the specialization
of mental functions in general.

The obtained 'raw' correlation for (2) is .$% ± .1 Allowing for the
mixture of the sexes, the inaccuracies of the original measures, and the
individual variations in the experiences upon which the memories for
twenty-four hours were based, I estimate the relation as .8 ± .1. I
know of no other measure of the relation between brief and long reten-
tion in the case of unconnected material. Henderson, in the case of
connected trains of thought, gives data for memory over a few
minutes from three minutes' study and memory of the same material
after forty-eight hours, based upon the three minutes' study and the
experience of writing out what was remembered at its close. The
resulting correlations would seem, if corrected for attenuation on the
one hand, and for mixture of the sexes and of differently selected
groups on the other, to be about .9.

The relation between retention of the effects of an experience for
one or two minutes and their retention for one or two days thus
seems to be one of the closest yet measured in human nature.