Maintenance of knowledge: Questions about memory we forgot to ask

Abstract

Used 2 methods—successive relearning and cross-sectional adjustment—to examine processes involved in the maintenance of knowledge. Successive relearning is illustrated in a laboratory study with 90 undergraduates; English–Spanish word pairs were periodically relearned, and the intersession interval was varied from a few seconds to 30 days. It was found that indefinite access to the acquired information remained highly probable if the retraining interval did not exceed the access interval. Cross-sectional adjustment is a nonlaboratory method designed to investigate the acquisition and maintenance of complex knowledge systems under ecologically realistic conditions. The method is illustrated in a study with 275 university students and 576 alumni in which maintenance of knowledge of a city was found to be related to the frequency, recency, duration, and distribution of visits during a 46-yr retention interval. Statistical and interpretive procedures for each method are detailed. (9 ref) (PsycINFO Database Record (c) 2012 APA, all rights reserved)

Full text

Journal
of
Experimental
Psychology:
General
1979,
Vol. 108,
No. 3,
296-308
Maintenance
of
Knowledge:
Questions About Memory
We
Forgot
to Ask
Harry
P.
Bahrick
Ohio
Wesleyan
University
SUMMARY
Memory
research
has
contributed little toward understanding acquisition, main-
tenance,
or
loss
of
complex knowledge systems. This
is so
because such systems
are
acquired
and
maintained over long time periods
that
cannot
be
accommodated
by
traditional research methods. Acquisition
of
semipermanent knowledge typically
involves repeated
exposure
to
information, with
losses
of
information during
in-
tervals between exposures. Continued maintenance
of
knowledge depends
on pe-
riodic
access.
Two
methods
are
described
to
investigate these processes.
The
method
of
successive relearning
is a
laboratory method illustrated
in a
study
in
which English-Spanish word pairs
are
periodically relearned
and the
effect
of
varying
the
intersession interval
from
a few
seconds
to 30
days
is
estab-
lished.
It is
shown
that
indefinite
access
to the
acquired
information
remains highly
probable
if the
retraining interval does
not
exceed
the
access interval.
If the
access
interval
is
much longer than
the
retraining interval, much
of the
acquired informa-
tion becomes inaccessible during
the
access interval.
The
method
of
cross-sectional adjustment
is a
nonlaboratory method designed
to
investigate
the
acquisition
and
maintenance
of
complex knowledge systems
under ecologically realistic conditions. This method
can be
used
if a
large
number
of
individuals
acquired
the
same information,
if the
time
of
acquisition dates back
from
a few
months
to
many years,
and if
both
the
original level
of
knowledge
and
the
degree
of
rehearsal during
the
retention interval
can be
estimated with
ac-
ceptable reliability.
The
method
is
illustrated
in a
study
in
which maintenance
of
knowledge
of a
city
is
related
to the
frequency,
recency,
duration,
and
distribution
of
visits during
a
46-yr. retention interval.
Subjects
are
assigned
to
time
groups
based
on how
long
ago
they
acquired
the
information;
average
retention performance
for
various time groups yields
an un-
adjusted
retention
curve.
Such
curves
must
be
corrected
for
differences
among
the
groups
in the
degree
of
original learning
and in the
amount
of
rehearsal.
These
adjustments
are
made
on the
basis
of
multiple
regression
equations
that
reflect
correlations
of
rehearsal variables
and
retention performance.
It is
shown that
the
adjustment
process
can
correct
for
major
inequalities
among
groups.
The
multiple
regression equations
are
used
further
to
obtain estimates
of the
amount
of re-
hearsal
necessary
to
maintain
the
original
level
of
knowledge.
Copyright 1979
by the
American
Psychological
Association,
Inc.
0096-344S/79/0803-0296$00.7S
296