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RECALL VERSUS RECOGNITION A study of episodic memory retrieval

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RECALL VERSUS RECOGNITION  A study of episodic memory retrieval Powered By Docstoc
					  Recall Versus Recognition: A study of the superior means of episodic
                           memory retrieval

                                        John Biddle
                                   Charles Sturt University

The aim of this study was to find evidence that proved retrieval by means of recognition
would be significantly greater then retrieval by recall in the episodic memory retrieval
process. 20 first year Undergraduate psychology students, (5 males and 15 females)
participated in an experiment that involved splitting the students into two groups of 10. A
list of 15 words was displayed briefly on an overhead projector; a 5 second delay
followed the display before students were asked to retrieve as many of the list words as
they each found possible. 10 of the students were given a list of 30 words containing the
15 that were displayed, to aid them as a cue for recognition of those words. The other 10
students were given no aid, thus relying purely on their recall skills to retrieve the list
words. The results of the experiment proved inconclusive, as there was no significant
difference found between the number of words each group were able to retrieve.


Episodic memory has been described as the storage and retrieval of temporally dated,

spatially located, and personally experienced events and episodes, and temporal-spatial

relations among such events (Tulving & Thomson 1973). The two means of the episodic

memory retrieval process, recognition and recall is an area that has been the focus of

many previous studies. Examined intensely is which means of retrieval is most effective.

Testing the memory process involves looking at to what extent participants are able to

encode, store and retrieve new data. To test recall ability a participant relies on their own,

unaided ability to retrieve as much of a series of input data as possible. To test

recognition, participants are given cues to aid them in retrieving the input data. Studies

have shown that recall ability is limited to the general rather than the specific (Van

Koppen & Lochun, 1997). Reflecting this is that concrete words are proven to be more

easily recalled than abstract words (Walker & Hulme, 1999), and that in list compositions

high frequency words are recalled better then low frequency words (Clark & Burchett,

1994). Stimulating recall by use of cues has been shown to boost the recall process


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(Dubow, 1995). The general implication arises from these studies that if recall ability is

limited as shown, then memory retrieval by means of recognition will prove the more

effective process.


To provide more direct evidence that recognition is the superior means of the episodic

memory retrieval process, an experiment involving participants in recall and recognition

groups (though each participant will be individually tested), needs to be conducted. The

two groups will be shown at the same time, briefly, a series of list words. The recall

group will individually be asked to retrieve unassisted the list words while the

recognition group will be aided by the use of extralist cuing in retrieving the same words.

Results of the experiment should provide a clearer implication of the superior means of

memory retrieval to support the hypothesis.


Extralist cuing has been used in previous studies (Thomson & Tulving, 1970, Tulving &

Thomson, 1973) for facilitating the recall of list words by using retrieval cues that were

not part of the input list. The effectiveness of cuing has been discussed in those studies,

however, theoretically, cues used for this experiment should be effective in the

facilitation of recall by recognition. This could mean that significant evidence will be

found to prove that recognition will be greater then recall in the episodic memory

retrieval process.

Other factors (variables) that could affect results in testing this hypothesis will be

discussed in the last section of the report.




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                                         METHOD

Participants: 20 participants were involved in the experiment. Participants consisted of 5

male and 15 female first year, undergraduate psychology students from Charles Sturt

University. Participants were split into two groups of 10 constituting Recall and

Recognition groups. Each participant was tested individually in these groups.

Materials and Procedure: 20 participants were split into two groups of 10 to make up

Recall and Recognition groups. Each individual participant were given sheets of paper,

the recall groups sheet’s being blank, the recognition group’s sheet containing a list of

words that was placed face down so that they could not read them. It was explained to all

participants that the groups alternatively would have to recall or recognise as many words

as possible from a list to be displayed by the experimenter. An overhead projector in the

center of the room was set up for the experiment and it was made sure that each

participant was able to see its projection. The experimenter displayed one by one for 3

seconds each a list of 15 words on the projector. Following the display, the experimenter

imposed a 5 second delay. Participants were then told that they were to begin the retrieval

of as many of those words as they were able to. The Recall group would rely on their

unaided ability to do so, The Recognition group used the list of words given to them

containing the 15 input words as well as a number of other irrelevant words to aid their

ability of retrieval. After satisfying that the participants had reached their extent, the

experimenter revealed the full list of words to the participants who were asked to mark

how many words that they were able to recall or recognise correctly. Each participant’s

individual score was recorded in a table under the headings of Recall or Recognition


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depending on the group they were in. The experimenter calculated each list of scores to a

total, then divided each by 10 to find the average number of words recalled by each

group. A T test was run to indicate if there was significant difference between the two

groups scores from which a conclusion could be made. Results were displayed in a table.


                                         RESULTS

Results from the experiment are displayed in the following table:

Group         No. participants     Mean of Results      Standard Deviation
Recognition            10               13.6                 0.97
Recall                 10               12.9                 1.72

Table 1. Results of experiment.

The results of the T Test are as follows: t(18)=1.18, p>.05.

Results indicate that there is no significant difference between the recall and recognition

groups ability in memory retrieval.


                                  GENERAL DISCUSSION

The results mean that determining whether or not recognition is the superior means for

the episodic memory retrieval process is inconclusive. Although there was a difference in

favour of recognition over recall in the results, that difference is not significant enough to

prove the hypothesis correct. The discussion will seek to identify both dependant and

independent variables that may have contributed to the results in an effort to derive

further implications from this and previous studies that may be tested in the future.


You can see from the results that the mean number of list words recalled or recognised is

very high for both groups as a figure out of 15. This result from the Recall group was

unexpected as it was implicated that the number of words they should have been able to


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recall would be a much smaller figure. Breen-Lewis & Wilding (1984) found that the

time of day attributes to recall ability. They found that in the afternoon their participants

performed better in memory recall tasks then in the morning on the same day, with their

expectations of the memory test in the afternoon also attributing to this. Participants

involved in the experiment for this report, sat for the experiment in the afternoon, this

was almost immediately after a morning lecture on memory involving all students who

attended the lecture doing similar memory recall tests. It could be speculated that their

individual results depended on the experiment being conducted at that time of day and

day of the week, following the lecture on memory to be as high as they were.


Walker & Hulme (1999), discuss how semantic and phonological coding of list words

exert an underestimated, yet great influence on short-term memory retrieval. It may be

important to study episodic memory retrieval with semantic memory retrieval in recall

and recognition because the participants may have depended on the sounds and meanings

of the list words to recall a high number of them. The results could also have depended

on the composition of the list words. Clark & Burchett (1994) have shown that high

frequency words were more easily recalled, did the list of word that was used contain

many high frequency words?


Independent of how and when the experiment was conducted, participants in the recall

group may have individually adopted strategies to increase their memory encoding,

retention and retrieval skills. They may also be people with great memory recall capacity,

it is not known but could account for their results.

As mentioned in this reports introduction, Thomson & Tulving (1970, 1973) have



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examined the effectiveness of cuing. It was found that extralists are effective as cues

when the participants expects a free-recall test but not when they expects to be tested for

list words with other list words. The Recognition group knew they were the recognition

group and would be given cues to aid them in their retrieval process before the

experiment was actually conducted. Their knowledge of this may have reduced the

amount of input words that they were able to recognise from the longer list of words they

were given. If this was the case then the results might have proved significant enough to

draw a conclusion on the hypothesis if participants remained unaware of any cue-aids

until they were asked to begin retrieving the list words. Their results as they stand,

though high, may have been completely dependant on this situation.


It is felt that the hypothesis still stands to be re-examined from this report, provided that it

is taken into greater consideration the factors that may have effected the final

inconclusive results. Past studies have laid the grounding for such an examination though

their implications and findings may prove it difficult to test the hypothesis in a way

similar to how the experiment for this research article was done.




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                                   REFERENCES

Tulving, E. & Thomson, D. (1973) Encoding specificity and retrieval process in episodic
memory. Psychological Review, 80, 352-373.

Van Koppen, P.J. & Lochun, S.K. (1997) Portraying perpetrators: The validity of
offender descriptions by witnesses. Law and Human Behaviour, 21 (6), 661-685.

Walker, I. & Hulme, C. (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, & Cognition, 25 (5), 1256-1271.

Clark, S.E. & Burchett R.R. (1994) Word frequency and list composition effects in
associative recognition and recall. Memory and Cognition, 22 (1), 55-62.

Dubow, J.S. (1995) Advertising recognition and recall by age – including teens. Journal
of Psychology, 35 (5), 55-60.

Breen-Lewis, K. & Wilding, J. (1984) Word frequency and list composition effects in
associative recognition and recall. British Journal of Psychology, 75 (1), 51-63.

Thomson, D. & Tulving, E. (1970) Associative encoding: Weak and strong cues. Journal
of Experimental Psychology, 86, 155-162.




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