An Experiment on Memory and the Effect of Different Levels of Processing.
AS Psychology Coursework
An Experiment on Memory and the Effect of Different Levels of Processing
Contents
Abstract 2
Introduction 3
Method 5
Results 8
Discussion 10
References 12
Appendix 1 14
Consent Form
Appendix 2 15
Standardised Instructions
Appendix 3 16
Sample Answer Sheet
Appendix 4 17
Word List
Appendix 5 18
Debriefing Sheet
Appendix 6 19
Raw Data
Appendix 7 20 Statistical Calculations
Abstract
This investigation is based on the Levels of Processing model of memory and the work of Craik and Lockhart which states that the deeper the processing used, the more likely the recall.
The aim of the study was to investigate the relationship between the level of processing required and the relative recall rates. The experimental hypothesis was that there will be a significant positive relationship between the depth of processing required, and the likelihood of the word's recall. The null hypothesis was that there will be no significant positive relationship between the depth of processing required, and the likelihood of the word's recall. An experimental research method was used with an independent measures design. The sampling method used was opportunity, the sample size was 10 males and 10 females, and they were all office workers from Cirencester.
The results showed no evidence of a positive relationship between the level of processing required and the likelihood of recall. On average 36.1% of words remembered required visual processing, 30.5% required acoustic processing and 34.9% required semantic processing.
Hence, the experimental hypothesis was rejected and the null hypothesis accepted. As the null hypothesis was accepted, the conclusion drawn was that the level of processing of information has no effect on its likelihood of recall.
Introduction
The origin of this study was the subject of Memory.
STM and LTM
In 1890 the American philosopher and psychologist, William James, suggested memory is split into two stores - short term (STM) and long term (LTM).
The short-term memory can be defined as holding information for a few seconds, basically until it has been used. George Miller (1956, as cited in Askam et al, 2000) described its capacity as 'the magical number seven, plus or minus two'. This means that experiments have shown that, on average, people remember between five and nine pieces of information, either individually or chunked.
The long-term memory differs in a few vital ways from the STM.
Firstly, it stores 'a person's knowledge of the world, their past life, and their plans for the future' (Askam et al, 2000 pg. 7). Also the LTM holds information for considerably longer than the STM; in fact the exact length of time is unknown, as is the capacity, both of which appear to depend on several factors including the apparent relevance of the information to the individual, and how frequently it is recalled.
Models of Memory
There have been various models of memory devised over the years. These try to provide a logical image of the memory processes and stores.
The first of these is the most influential Multi-Store Model, and devised by Atkinson and Shiffrin (1968, as cited in Gross, 1990), and is basis for all the other models.
The key point of this model is that the memory involves three stores linked by various processes.
Information is received by the senses and goes into the 'Sensory Store'. If this information is attended to, it passes to the STM Store; if not, it is lost. Within the STM store information is rehearsed, it then passes to the LTM store. If it is not rehearsed, it is lost. The final point in this model is that for information to be recalled from the LTM it must first be retrieved to the STM.
The Working Memory Model, created by Baddeley and Hitch (1974, as cited in Gross, 1990), aimed to provide a more detailed picture of the STM. They believed it contained many components or sub-systems each specialising in a particular task, with one, the so-called central executive, controlling the whole operation. This ultimately meant that the information did not just sit in the STM waiting to be passed into LTM, but it was constantly analysed and 'worked on'.
The final memory model, designed by Craik and Lockhart (1972, as cited in Gross, 1990), refers to how the information was encoded and processed rather than how it is transferred between stores. They found that information can be processed at different levels and that the more it is processed; the better it is remembered.
In order to support this, they carried out an experiment that looked at visual, acoustic and semantic processing. They gave their participants some cards with questions about a certain word. These either required visual, e.g. 'Is this word in upper case? BOAT'; acoustic, e.g. 'Does this rhyme with leaf? TIN'; or semantic, 'Is PAPER an animal?'. Later they were asked to recall the words.
From this experiment Craik and Lockhart found that the words that were processed in a deeper way, in other words, semantically - by meaning, were more likely to be recalled than acoustically processed words, and even more likely to be recalled than visually processed words, as these require the least processing.
Since then, this experiment has been repeated many times, and has been with this study. The aim of which was to investigate the relationship between the level of processing required and the relative recall rates.
Hypotheses -
Experimental Hypothesis
There will be a significant positive relationship between the depth of processing required, and the likelihood of the word's recall.
Null Hypothesis
There will be no significant positive relationship between the depth of processing required, and the likelihood of the word's recall.
Method
Design
The hypothesis for this study was ...
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Since then, this experiment has been repeated many times, and has been with this study. The aim of which was to investigate the relationship between the level of processing required and the relative recall rates.
Hypotheses -
Experimental Hypothesis
There will be a significant positive relationship between the depth of processing required, and the likelihood of the word's recall.
Null Hypothesis
There will be no significant positive relationship between the depth of processing required, and the likelihood of the word's recall.
Method
Design
The hypothesis for this study was investigated using a field experiment. An experiment tests a hypothesis by altering and measuring one variable in a controlled atmosphere. A field experiment is less controlled than if it was carried out in a laboratory. However, as it uses the participant's natural environment, what it loses in control, it makes up for in ecological validity.
The experiment used independent measures design because the nature of the experiment does not require nor enable the use of repeated measures. This is because the experiment is not looking at several sets of different conditions which require individual testing, but involve all three conditions (the different levels of processing) in the single trial. If the experiment had not been of this nature it would have been preferable to use repeated measures as it increases reliability. Also as the time allocated for data collection was quite tight, independent measures meant that the experiment only needed to be carried out once. Independent measures involves using each participant only once whereas repeated measures tests the participants in several different conditions.
20 participants were tested in total, 10 of whom were male and 10 female. As it was carried out using independent measures each participant performed in one trial.
The Independent Variable (IV) can be defined as any variable that is manipulated by the researcher. This is usually the variable referred to in the hypothesis. In this case, it is the level of processing the question requires, i.e. semantic, acoustic or visual processing.
The Dependent Variable (DV) can be defined as the variable, affected by change in the independent variable, which is measured by the researcher. The dependent variable for this study is the relative recall rate of each type of question. In other words, it is the percentage of words remembered within each level of processing.
Extraneous or Confounding Variables are any variable, other than the independent variable, which may affect the dependent variable. It is for this reason that it is necessary to attempt to control these variables as much as possible in order to reduce any outside influences that could affect the result. For this study, a possible extraneous variable is distraction caused by noise, activity or otherwise which could break concentration and reduce the quantity of words that are remembered. In an attempt to control this variable, the experiment was carried out in a quiet, empty room.
Another possible extraneous variable is that if the participants received different instructions, they may misunderstand; not receive full instructions; or have an advantage or disadvantage in some way. In order to combat this, a set of Standardised Instructions were written so that every participant received the same information. See Appendix 2.
If the participants are aware of the nature and hypothesis of the experiment demand characteristics may become apparent. Therefore they were only informed of the general topic, memory, of the experiment and any further information was saved for the debriefing. As they were informed of the topic prior to the experiment they were in no way deceived but demand characteristics were kept to a minimum.
Participants
As mentioned before, 20 participants were tested; 10 male and 10 female. Their age ranged from 16 to 60 years of age.
The participants were selected using opportunity sampling. This means the researcher uses subjects who are around and available at the time. It was chosen as it is a quick, convenient, and easy method however can demonstrate some bias if careful consideration is not employed.
A Target Population is the collection of people participants are chosen from, and the group to whom the results are usually generalised towards. The Target Population in this study were office workers in Gloucestershire and all took part in an office environment.
Apparatus and Materials
The following items were used in the experiment:
* Stopwatch
* Pen
* Answer Sheets (See Appendix 3)
* Consent Forms (See Appendix 1)
* Standardised Instructions (See Appendix 2)
* Debriefing Sheet (See Appendix 5)
* Word List - created using 18 words (six three letters, six four letters, and six five letters) chosen at random from a dictionary (See Appendix 4). Each word was teamed with a question which would require either acoustic, visual or semantic processing. Six of each type of question was used, three of which could be answered 'yes' and three 'no' to stop any extraneous variable caused by any bias.
Procedure
The participants were taken into a quiet, empty room and were asked to read and sign a consent form. This detailed their rights for example confidentiality and withdrawal. A copy of this is included as Appendix 1.
Once they had consented, they were given an answer sheet (see Appendix 3) and asked to complete the questions at the top. These were included for analysis purposes and related to age group and gender.
The participants were then read the rest of the Standardised Instructions (See Appendix 2) and asked if they had any questions before the experiment began. The researcher then gave the participant a word list to look at for one minute. After the minute was up, the researcher took away the word list and asked the participant to write down as many words as possible that they could remember from the list on their answer sheet. No time limit was given for this activity because it is irrelevant how long it took to recall and also so that the participant did not feel pressured which may have affected the recall.
Once the participant decided they could not remember anymore words, the researcher collected the answer sheet in and provided the debriefing (See Appendix 5). This gave further details of the experiment, including its nature and hypothesis, reminded the participants of their anonymity and gave them an opportunity to ask any further questions.
Ethical Considerations
There were several ethical issues that were particularly relevant to this study.
One of these was the necessity to obtain informed consent from the participants prior to the experiment. It is relevant to this experiment as it is always important that the participants are willing to take part and it informs them of their rights and, most importantly, ensures their safety. This issue was overcome by the use of a consent form (see appendix 1).
Also on this topic, was the issue of age of consent. At what age is a child's understanding sufficient to be able to give informed consent. To remove this problem, only participants over the age of 16 were selected for this study.
Another ethical consideration is the right to withdraw from the experiment. It is important that the participants have this right, and that they are aware of it, to protect them from harm. In order to suffice this, the participants were informed of their rights in the consent form, which they signed prior to starting the experiment.
The participants were informed that their results would be kept anonymous and confidential. This ensures their safety.
In studies where the participants are aware that they have taken part in an investigation, it is imperative that the participants are provided with any information that will complete their knowledge of the experiment. Therefore, a debriefing sheet (see Appendix 5) was designed in order to inform the participants of the nature of the experiment.
The procedure was written in accordance to the BPS ethical guidelines.
Results
All raw data can be found in Appendix 6.
Below is a table summarising the results of the study. It shows the percentage of the words remembered within each level of processing.
Level of Processing
Mean (%)
Median (%)
Mode (%)
Range (%)
Standard Deviation (%)
Visual
36.1
33.3
25
49.9
3.1
Acoustic
29.0
28.6
28.6, 33.3
50.0
2.7
Semantic
34.9
37.0
37.5
50.0
0.9
The graph below shows the mean percentage recall of words involving each different level of processing.
The highest mean percentage of the words remembered required visual processing and the lowest required semantic processing. The highest median percentage of the words remembered required semantic and the lowest required acoustic processing. The highest mode percentage of the words remembered required semantic processing and the lowest required visual processing.
The ranges for each level of processing were virtually the same, although the range for visual processing was slightly lower. The standard deviation of the percentage of the words remembered was lowest for semantic processing and highest for visual processing.
These results do not support Craik and Lockhart's original study, therefore the null hypothesis is accepted, as the results provide no significant conclusions.
Discussion
The results of this study were inconclusive as the different averages gave evidence for different conclusions. This forced the null hypothesis to be accepted.
Null Hypothesis - There will be no significant positive relationship between the depth of processing required and the likelihood of the word's recall.
Craik and Lockhart's original study (1972, as cited in Gross, 1990) which investigated how levels of processing affected recall has not been supported by the results of this study.
Their results showed that things requiring semantic processing were significantly better, and things that require visual processing were remembered significantly worse, than those that required acoustic processing.
The reason this study does not support Craik and Lockhart's is mostly due to lack of time and equipment that restricted the study in many ways.
Due to the setting of the experiment (an empty room in an office) and the fact that the participants stopped work for a few minutes to take part, it is understandable that their minds may have been on other things and their concentration would not necessarily be fully on the experiment. Therefore this may have affected their memory.
Another limit to this study is the sampling method. This study used opportunity sampling, which is not going to give particularly reliable and accurate results that may be generalised to a specific group in quite the same way others might.
The final crucial limitation is something that many of the participants mentioned in the debriefing.
It appears not enough emphasis was put on the relevance of the questions and too much was placed on remembering the words and therefore lots of the participants admitted to using the questions at the start but soon gave up when they failed to be of any obvious help. They then just read through the words in order to remember them and ignored the questions completely.
Also the word list itself contained too many variations of the appearance of the words, which were used in an attempt to make the visual questioned words less obvious to remember, but may have either added a visual element to the other types of words or simply confused the participant.
It seems time also played a part in encouraging this behaviour as several participants also mentioned that as they knew time was limited, but were not aware how much time was left, and feeling that the questions slowed down the learning, they resolved to just read through the words.
If the experiment was carried out again several measures could be employed to reduce these limitations.
The experiment could be carried out in a different environment, to reduce the distraction of work. For example, still using office workers, it could be done at the weekend at a different location. This would hopefully reduce the limitation of the participant's minds being on other things.
In order to increase the reliability and the ability to generalise the results, a different sampling method could be used, preferably stratified. This would mean the participants would be more equal in ability and such like, and would therefore make the results easier to generalise. However more time would be required in which to do this.
To solve the problem of participants ignoring the questions it would be necessary to do three things.
Firstly the standardised instructions would have to be changed to stress the relevance of the questions.
Secondly it may further emphasise the questions if the layout of the wordlist was changed. Altering the appearance of the words may also reduce the aid of extra visual processing to non-visual processing words.
Lastly it would help both the participants and ultimately the results if the participants were kept aware of the time remaining by either regular reminded by the experimenter or by the presence of a stop clock.
There are several aspects of this experiment worthy of further investigation. It would be interesting to study different types of people's memory, for example different intelligence levels, which may show how or if intelligence is acquired; people in different types of jobs; different personality types; or the memories of mentally ill or psychologically damaged participants, which may provide an insight into treatment and learning of such people. It may also prove interesting to look at how different types of words are remembered and whether spoken or written information is remembered best.
If this study had shown the same results as the original by Craik and Lockhart, it would be particularly relevant to society, mainly in terms of education. This is because it shows that things that require semantic processing are more likely to be remembered. Therefore learning methods should be used which require the students to think about the meanings of things they are learning, and they will be less likely to forget it.
Overall Conclusion
The results of this investigation accept the null hypothesis, which shows that the level of processing of information has no effect on its likelihood of recall. These findings do not support the findings of Craik and Lockhart. This conclusion was caused by many limitations such as the experimental environment, the sampling method and participants disregarding the questions.
References
Askam, W., Foreman, N., Haralambos, M., Jones, S., Rice, D. (2000) Psychology In Focus AS Level. Haddington, East Lothian: Scotprint
Eysenck, M., Keane, M. (1990) Cognitive Psychology: A Student Handbook. East Sussex: Lawrence Eribaum Associates Ltd
Gross, R.D. (1990) Key Studies in Psychology. London: Hodder and Stoughton Educational
Lloyd, P., Mayes, A. (1984) Introduction to Psychology - An Integrated Approach. London: Fontana Paperbacks
British Psychological Society - www.bps.org.uk
Appendix 1
Thank you for volunteering to take part in this experiment. You will not be asked to proceed any further until you have read and signed this form.
This experiment investigates memory. You will be fully debriefed with more details about the experiment after it has been carried out.
Your results will remain anonymous and confidential.
If at any time you feel unsure or uncomfortable with the experiment please do not hesitate to ask questions. You have the right to withdraw from the experiment at any time.
I have read and understood the above information and agree to participate in the psychological experiment.
Signed ...................................................... Date....................................
Appendix 2
Standardised Instructions
Before we get started I need you to sign this consent form. Basically it just ensures you know your rights as a participant and proves you knowingly agreed to take part.
Here is an answer sheet. Can you answer the questions at the top please.
In a moment I will be giving you a word list. This consists of 18 words each with a related question which can be answered yes or no. An example of this is: "FISH - Is this word a mode of transport?" What I want you to do, is read through the sheet and answer the questions in your head. The questions are designed to help you remember the words. I will give you 1 minute in which to do this.
After the minute is up, I will take away the list and ask you to write down as many of the words as possible that you can remember.
And that's all you have to do.
Try not to feel pressured by the number of words to remember, I do not expect you to remember anywhere near that many.
Before we get started, have you any questions you'd like to ask me?
Appendix 3
Answer Sheet
Are you: Male Female
What is your age bracket:
16 - 20 31 - 40 51 - 60
21 - 30 41 - 50
Use the space below to write as many words as you can remember from the list:
Thank You
Appendix 4
ferry Is this word in upper case?
Cup Is this something you drink from?
HEN Does this rhyme with 'pen'?
desk Is this word underlined?
Name Does this rhyme with 'shoe'?
Big Is this a form of clothing?
learn Is this done in schools?
pear Does this rhyme with 'dare'?
VAULT Is this in lower case?
Fox Is this something in the home?
LIGHT Is this word in capitals?
Wash Does this rhyme with 'chair'?
Clock Does this show the time?
ADD Is this in italics?
Love Does this rhyme with 'ladder'?
place Is this an activity?
What Is this in bold?
Sun Does this rhyme with 'run'?
Appendix 5
Debriefing
Thank you for taking part in this experiment.
Its aim was to test how the level at which information is processed affects how well it is remembered.
Everyone who took part in the experiment had the same instructions and procedure as you.
It was hypothesised that the words where you were questioned about its visual appearance would remembered worst, and then words where you were questioned about its sound and the words you were questioned about its meaning would be remembered best.
Your results will be analysed along with the others. They will be kept anonymous and confidential at all times.
If you have any further questions please do not hesitate to ask.
Appendix 6
Raw Data
Participant
Number of Words Recalled
Semantic
Acoustic
Visual
2
2
3
2
2
2
3
3
3
2
2
4
2
2
2
5
3
2
2
6
2
4
7
4
4
3
8
3
2
9
0
2
2
1
2
3
2
3
2
3
3
3
4
4
2
0
2
5
3
4
6
6
3
3
7
2
4
2
8
3
3
2
9
2
4
2
20
0
2
Appendix 7
Statistical Calculations
Based on percentage recall
Mean
Semantic -
28.6+36.4+50+37.5+33.3+25+40+33.3+37.5+50+42.8+33.3+37.5+42.8+28.6+50+25+28.6+0+37.5
= 697.7
697.7( 20 = 34.9%
Acoustic -
4.3+36.4+33.3+37.5+33.3+50+20+50+25+25+28.6+33.3+12.5+28.6+28.6+0+ 50+28.6+12.5+33.3
= 580.8
580.8( 20 = 29.0%
Visual -
57.1+27.2+16.7+25+33.3+25+40+16.7+37.5+25+28.6+33.3+50+28.6+42.8+50+25+42.8+50+66.6
= 721.2
721.2( 20 = 36.1%
Median
Semantic -
0 25 25 28.6 28.6 28.6 33.3 33.3 33.3 36.4 37.5 37.5 37.5 37.5 40 42.8 42.8 50 50 50
36.4+37.5 = 37.0%
2
Acoustic -
0 12.5 12.5 14.3 20 25 25 28.6 28.6 28.6 28.6 33.3 33.3 33.3 33.3 36.4 37.5 50 50 50
28.6+28.6 = 28.6%
2
Visual -
6.7 16.7 25 25 25 25 27.2 28.6 28.6 33.3 33.3 37.5 40 42.8 42.8 50 50 50 57.1 66.6
33.3+33.3 = 33.3%
2
Mode
Semantic - Acoustic - Visual -
%
Tally
0
|
25
||
28.6
|||
33.3
|||
36.4
|
37.5
||||
40
|
42.8
||
50
|||
%
Tally
0
|
2.5
||
4.3
|
20
|
25
||
28.6
||||
33.3
||||
36.4
|
37.5
|
50
|||
%
Tally
6.7
||
25
||||
27.2
|
28.6
||
33.3
||
37.5
|
40
|
42.8
||
50
|||
57.1
|
66.6
|
= 37.5
= 28.6 and 33.3
= 25
Range
Semantic - 50 - 0 = 50%
Acoustic - 50 - 0 = 50%
Visual - 66.6 - 16.7 = 49.9%
Standard Deviation
( = ((²
n
Semantic -
((²= 28.6²+36.4²+50²+37.5²+33.3²+25²+40²+33.3²+37.5²+50²+42.8²+33.3² +37.5²+42.8²+28.6²+50²+25²+28.6²+0²+37.5²
= 26744.19
( = 26744.19
20
= 10.9%
Acoustic -
((²= 14.3²+36.4²+33.3²+37.5²+33.3²+50²+20²+20²+25²+25²+28.6²+33.3² +12.5²+28.6²+28.6²+0²+28.6²+50²+28.6²+33.3²
= 20105.6
( = 20105.6
20
= 12.7%
Visual -
((²= 57.1²+27.2²+16.7²+25²+33.3²+25²+40²+16.7²+37.5²+25²+28.6²+33.3² +50²+28.6²+42.8²+50²+25²+42.8²+50²+66.6²
= 29517.22
( = 29517.22
20
= 13.1%
An Experiment on Memory and the Effect of Different Levels of Processing
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