|dc.description.abstract||Traditional psychometric theory and practice classify
people according to broad ability dimensions but do not examine
how these mental processes occur. Hunt and Lansman
(1975) proposed a 'distributed memory' model of cognitive
processes with emphasis on how to describe individual differences
based on the assumption that each individual possesses
the same components. It is in the quality of these components
~hat individual differences arise. Carroll (1974) expands
Hunt's model to include a production system (after Newell and
Simon, 1973) and a response system. He developed a framework
of factor analytic (FA) factors for : the purpose of describing
how individual differences may arise from them. This
scheme is to be used in the analysis of psychometric tes ts .
Recent advances in the field of information processing
are examined and include. 1) Hunt's development of differences
between subjects designated as high or low verbal ,
2) Miller's pursuit of the magic number seven, plus or minus
two, 3) Ferguson's examination of transfer and abilities and,
4) Brown's discoveries concerning strategy teaching and
In order to examine possible sources of individual
differences arising from cognitive tasks, traditional psychometric
tests were searched for a suitable perceptual task
which could be varied slightly and administered to gauge
learning effects produced by controlling independent variables.
It also had to be suitable for analysis using Carroll's
f ramework . The Coding Task (a symbol substitution test) found
i n the Performance Scale of the WISe was chosen.
Two experiments were devised to test the following
hypotheses. 1) High verbals should be able to complete significantly
more items on the Symbol Substitution Task than
low verbals (Hunt, Lansman, 1975). 2) Having previous practice
on a task, where strategies involved in the task may be
identified, increases the amount of output on a similar task
(Carroll, 1974). J) There should be a sUbstantial decrease
in the amount of output as the load on STM is increased
(Miller, 1956) . 4) Repeated measures should produce an increase
in output over trials and where individual differences
in previously acquired abilities are involved, these should
differentiate individuals over trials (Ferguson, 1956).
S) Teaching slow learners a rehearsal strategy would improve
their learning such that their learning would resemble that
of normals on the ,:same task. (Brown, 1974).
In the first experiment 60 subjects were d.ivided·into
high and low verbal, further divided randomly into a practice
group and nonpractice group. Five subjects in each group
were assigned randomly to work on a five, seven and nine
digit code throughout the experiment. The practice group
was given three trials of two minutes each on the practice
code (designed to eliminate transfer effects due to symbol
similarity) and then three trials of two minutes each on
the actual SST task . The nonpractice group was given three
trials of two minutes each on the same actual SST task .
Results were analyzed using a four-way analysis of variance .
In the second experiment 18 slow learners were divided
randomly into two groups. one group receiving a planned
strategy practioe, the other receiving random practice. Both
groups worked on the actual code to be used later in the
actual task. Within each group subjects were randomly assigned
to work on a five, seven or nine digit code throughout. Both
practice and actual tests consisted on three trials of two
minutes each. Results were analyzed using a three-way
analysis of variance .
It was found in t he first experiment that 1) high or
low verbal ability by itself did not produce significantly
different results. However, when in interaction with the
other independent variables, a difference in performance
was noted . 2) The previous practice variable was significant
over all segments of the experiment. Those who received
previo.us practice were able to score significantly higher
than those without it. J) Increasing the size of the load
on STM severely restricts performance. 4) The effect of
repeated trials proved to be beneficial. Generally, gains
were made on each successive trial within each group.
S) In the second experiment, slow learners who were allowed
to practice randomly performed better on the actual task
than subjeots who were taught the code by means of a planned
Upon analysis using the Carroll scheme, individual
differences were noted in the ability to develop strategies
of storing, searching and retrieving items from STM, and
in adopting necessary rehearsals for retention in STM. While
these strategies may benef it some it was found that for
others they may be harmful . Temporal aspects and perceptual
speed were also found to be sources of variance within
Generally it was found that the largest single factor
i nfluencing learning on this task was the repeated measures .
What e~ables gains to be made, varies with individuals .
There are environmental factors, specific abilities, strategy
development, previous learning, amount of load on STM ,
perceptual and temporal parameters which influence learning
and these have serious implications for educational programs .||en_US