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This
study focuses on the serial position curve and what happens when we interfere
with the primacy and recency effect. The design of the study was based on
Murdock’s experiment for the serial position curve, which illustrates the
stage theory of memory.
The
stage theory of memory proposed by Waugh and Norman (1965) asserts that
information goes through a sensory register before entering Short Term Memory (STM).
If information in STM is not lost through decay or displacement it has the
potential to enter Long Term Memory (LTM). Interference can play a role in
information being lost from STM, as research indicated that the presentation
rate of information did not affect performance. It is debatable that the sensory
register exists and theorists often leave it out of stage theory of memory.
STM
is regarded as having a capacity of seven plus or minus two pieces of
information. It is believed that the seven items are not size limited as smaller
pieces of information can be recoded into larger pieces to form the capacity of
the STM. This is called ‘chunking’. Miller (1956) proposed the theory of the
magic number seven and chunking. Mednick (1964) claimed that people tend to
recall meaningful units, not letters or numbers. Glazner and Cunitz (1966)
indicated that STM is not limited to size capacity but to the amount of time
that the STM can hold an item of information.
The
Serial Position Curve is a psychological phenomena presented by Murdock (1962)
as an experiment where participants were shown a list of words and then tested
for recall. This experiment has become an accepted measure of memory testing.
The theory behind the serial position curve is that people recall words better
at the beginning or end of a wordlist. A better recall at the beginning is an
example of the primacy effect whereas a better recall at the end is an example
of the recency effect. Additionally, the distinctiveness effect refers to
distinctly different items remembered regardless of position.
This study aims to replicate the serial position curve and examine the primacy and recency effects. Part 2 and 3 of this study replicates Glazner and Cunitz study conducted in 1966. Glazner and Cunitz show the presentation of words does affect the shape of the serial position curve. Glass et al. (1979) theorised that if a participant if given a distractor task before recalling the list, then the recency portion of the curve will suffer. Craik (1970) and Hulme et al. (1997) results showed that an item of information is strong and highly accessible immediately after being presented but its retention falls rapidly as further items of information are presented.
The
object of the study was to test three hypotheses through three tests.
These are:
Hypothesis one: To attempt to recreate Murdocks (1962, 1974) Serial Position Curve
Hypothesis two: To attempt to reduce the effect of recency due to displacement
Hypothesis
three: To attempt to diminish the affect of primacy due to the inability to
rehearse (faster presentation).
The
quantitative methodology employed in this study was chosen because it is a
quality tool for testing memory. The test has proven to be simple yet effective
in achieving results.
In
this study the Independent variable represents the way the words are presented (exposure
time, Inter-Trial Interval and distracting task). The Dependent variable is
the number of words that the participant recalls correctly.
An
extraneous variable in this experiment could have been the person’s ability to
focus on the task at hand. Giving participants a focusing task similar to the
experiment before beginning could assist in this.
1.Particpants
Participants
were drawn from PSY101tutorial group. The group comprised of 15 participants, 2
male and 13 female. All the participants were first year teaching/psychology
students attending Charles Sturt University, Bathurst.
2.Materials
Materials
used included an overhead projector, statistascope screen, paper, pens and
overheads containing the lists of words. The statistascope allowed the
experimenter to display each word on the list without revealing any other words.
3.Procedure
The
experimenter tells the participants to label pieces of paper from one to four.
The researcher explained that participants will be shown a list of twenty words
on the overhead projector, one at a time. As the words are shown, the
participants are told to attempt to memorise each word.
Part
1: The first list shown will attempt to achieve results that replicate the
Serial Position Curve.
To
show the first list to the participants, the experimenter moves the list of
words through the statistascope. The words are shown for 1 second with an
inter-trial interval (ITI) of 2 seconds.
Once all the words have been shown the experimenter immediately asks the participants to write down as many of the words they can recall on the first sheet of paper.
Part
2: This is an attempt to eliminate or reduce the recency effect but not the
primacy effect.
The
experimenter presents the second list in the same manner as the first list – 1
second showing followed by a 2 second ITI.
Once
the list has been shown, the experimenter asks participants to count backwards
from 95 in threes, writing this down on their second piece of paper.
Participants are given thirty seconds to do this.
The
experimenter then gets the participants to write down as many of the words from
the second list that they can recall. Allow two minutes for the participants to
do this and then get them to put the third sheet of paper aside.
Part
3: This is an attempt to reduce the primacy effect, but with minimal influence
on the recency effect.
With
the third list the experimenter again moves the list of words through the
statistascope at a quicker pace. The words are still presented for 1 second but
only have a 0.5 second ITI.
Once
all the words on the list have been shown immediately ask the participants to
write down words they recall on the fourth sheet of paper. Allow two minutes for
them to do this.
Once
the raw data was collected the results were entered into a frequency chart to
illustrate the serial position curve. This was achieved by tabulating the
participants’ results, which then indicated the frequency of each recalled
word. The distribution of correct recall in the word lists demonstrates the
effect of different presentations or distracter tasks.
Results
The
first experiment was replicating the basic serial position curve. This was
achieved as there was a greater recall of words at the beginning of the list,
then a drop off in recall before gradually increasing towards the end.
The
second experiment aimed to reduce the recency effect. As illustrated there has
been a reduction in the number of participants who recall the last section of
the list. The graph indicates a greater recall in the middle section of the
wordlist.
The
third experiment aimed to reduce the primacy effect. The graph shows that at the
beginning there is less participants who recall the first words with more
participants recalling the last few words.
Overall
the recall of words became less as more words are presented. Experiment one had
a total recall of 162 whereas experiment two and three had a total recall of 139
and 108 respectively. The reduction of the recency effect.
In
replicating the serial position curve our results showed that there is a better
recall of words from the beginning and end of the list. This was shown with a
larger portion of the participants recalling the first three words. The recall
of words lessened until the 15th word when recall started to improve
again. In Craik’s (1970) study this was also true as he reported that
recollection of an item is strong and highly accessible following presentation
but begins to deteriorate rapidly as further items are presented to the
participant.
The
aim of the second test to reduce the recency effect by giving the participants a
distracter task at the end of the presentation of words was achieved. The recall
of the last section of words in the list was substantially lower. The primacy
effect was unchanged as shown in the results.
Mednick (1964) stated that a source of forgetting is the events that
occur between learning something and when we try to recall it.
An outstanding feature of the recall of this list was the proportionately
large amount of people who recalled the 7th word in the list. The
word itself was ‘Box” which is not a particularly outstanding word so it was
surprising that 11 participants recalled it.
The
third experiment aimed to try and reduce the primacy effect. As shown in the
results the primacy effect was greatly reduced but there was little or no change
to the recency effect as recall remained high. These results are consistent with
Glazner and Cunitz’s (1966) results indicating that the presentation of the
new words affects the shape of the serial position curve. These results indicate
that rehearsal does play an important role in retaining information in STM.
As
each list contained different words it could be said that this affected recall.
This could be because some words may have been more familiar therefore more
easily recalled. If the study had used the same words practice effects would
have been introduced. Another problem that could have been encountered was the
interference effect. By having different words in each list practice effects
were eliminated but the interference effect was introduced. Words shown
previously could have interfered with words that were presented later in the
list. Showing the lists in quick succession reduced the effects of boredom and
fatigue on participants.
For
a more consistent and efficient presentation it would be beneficial for the
experimenter to use Power Point to present the wordlists. This would be
advantageous to the experimenter as the presentation of the words could be
programmed for exact timing eliminating differences in list presentations.
Overall
the results do support the theory however they are not conclusive. As shown in
the graph, recall in each experiment became less. The hypotheses was confirmed
but more tests would need to be conducted to gain a significant result.
Craik,
F.I.M. (1970) The fate of primary memory items in free recall. Journal
of Verbal Learning and Verbal behaviour, 9, 143-148
Glazner,
M and Cunitz, A.R. (1966) Two storage systems in free recall. Journal
of Verbal learning and Verbal behaviour, 5, 351-360.
Glass,
A.L., Holyoak, K.J., and Santa, J.L. (1979) Chapter 5, encoding Information into
memory, In Cognition, Addison-Wesley,
Reading
Hill,
W.F. (1981) Chapter 15, The Operation of Memory, In
Principles of Learning: A Handbook of Applications. Alfred Publishing Co.,
Inc, Sherman Oaks California.
Mednick,
Sarnoff, A. (1964) Chapter 7, remembering and Forgetting, In
Foundations of Modern Psychology Series: Learning. Prentice
– hall, Englewood Cliffs, New Jersey.
Miller,
G.A. (1956) The magical number seven plus or minus two: Some limits on our
capacity for processing information. Psychological Review, 63, 81-97.
Peterson,
L.R. and Peterson, M.J. (1959) Short-term retention of individual verbal items. Journal
of Experimental Psychology, 58(3),
193-198.
Walker,
Ian and Hulme, Charles (1999) Concrete words are easier to recall than abstract
words: Evidence for a semantic contribution to short-term serial recall. Journal
of Experimental Psychology: Learning, Memory, an Cognition, 25 (5),
1256-1271.
Weitan,
W. (2001) Chapter 7, Human Memory, In Psychology Themes and Variations. Thompson learning, Stamford,
Connecticut.
http://www.louisville.edu/~jrpani01/PSYCH_322_SLIDES/Chapter_4_web/index.htm
http://ernest.carleton.ca/~jlogan/cognitive_course_1/intro5.htm#long_ter
Introduction
to Cognitive Psychology
http://users.stargate.net/~lastone/sepo.html
The SEPO (Serial Position) Test for Discerning the Possession of Special or Guilty Information
http://ferguson.bvu.edu/Lrn_Mem/recall.html
The
Serial Position Effect