There are five theories for forgetting, decay, displacement, retrieval failure, lack of consolidation and interference. Interference explains forgetting in the long term memory, confusion is caused by other similar memories, and one of these can dominate the other to cause forgetting. Interference splits into two parts, proactive and retroactive. Retroactive is when a new memory causes us to forget an old memory, and it is only once the old memory is needed that it becomes known interference has taken place. For example learning to drive an automatic drive vehicle after always driving a manual vehicle. Proactive interference is when a past memory gets in the way of learning a new memory. The process goes forward and recent information has trouble consolidating due to familiarity with long term memory the brain is comfortable with. An example of this is learning to play netball after having basketball in your long term memory.
Evidence of this theory is provided in McGeoch’s 1942 study to support proactive interference. In which there are two conditions with independent measures, one group had a rest period, one had to learn word list A. then both conditions were given list B to learn, and asked to recall list B. the results showed better accuracy and more correctly recalled words in the first condition, the controlled group. And in the second condition, the experimental group, proactive interference occurred as list A caused them to forget and make mistakes in list B.
AIM
Carry out an experiment on participants to investigate proactive interference on memory recall, using McGeoch’s 1942 study as the basic format of the experiment. McGeoch’s research showed that proactive interference has a negative effect on memory recall, this experiment has a one tailed hypothesis because it is based on previous empirical evidence that suggests a certain outcome. This research is aiming on showing the same results, by experimenting on participants in two conditions, one controlled and one experimental. The null or alternative hypothesis will be retained depending on whether proactive interference occurred in condition 2 by the results being less than those in condition 1.
HYPOTHESES
The alternative hypothesis is that proactive interference will have a negative effect on memory recall of the word lists.
And the null hypothesis for this experiment is that proactive interference will make no significant difference on memory recall of the word lists.
METHOD
DESIGN
For the experiment a laboratory method was used, this is most scientific because manipulation of the independent variable indicates cause and effect and it increases accuracy and gives the experimenter great control of the variables. Repeated measures were used to keep subject variables to a minimum and keep the skill levels constant in both conditions. With the type of experiment chosen, each participant needs complete both conditions 1 and 2, otherwise there would be no proactive interference, because condition 1 acts as the interference during the second condition. There are less extraneous variables such as past experience and intelligence, which could have a large effect on the participants results, particularly with a small amount of participants. There is less variation between conditions, therefore the statistical tests are more accurate. Also, less participants were needed which in the circumstances of this experiment was beneficial.
The independent variable is the technique used, and the dependent variable is the results produced. In this experiment the independent variable is that in the second condition, condition 1 attempts to cause proactive interference. And the dependent variable was how many words were recalled from both conditions.
Extraneous variables are variables outside those that you are testing that could effect your results. The 15 participants that took part were all asked in similar conditions to each other, and were taking into an environment with minimal distractions and cheating was not possible. The answer sheet was kept out of sight. Participants were asked if they did psychology at the college or had any information on the nature of the research investigation. If any participants answered yes they would not of been wanted for the experiment.
Word frequency was a possible extraneous variable. More common words trigger a stronger memory recall. For the experiment 80 words were randomly selected by the experimenter from their mind. Then to eliminate these being linked in a familiar story (for instance if the experimenter said ‘dog’, it is quite likely the next word to come to mind would be ‘cat’), 30 of these words were randomly selected, without looking at the list to try to limit extraneous variables. The list was then checked to see if it looked adequate.
It is important to limit extraneous variables because they make the results produced less valid. It is unfair if extraneous variables occur and make it possible for some participants to achieve a better memory recall than others, due to anything other than their ability to recall the memory lists read to them. These variables were controlled by taking each participant individually into a quite room away from distractions or anyone else trying to help. Before they participated everyone was asked if they were or had studied psychology, or had any understanding of the coursework and experiments beings carried out.
PARTICIPANTS
The target population for the experiment were students at Truro College, none of which studied psychology, and all ages 16-19. All participants were found in the main college canteen. The sampling method used was opportunity sampling because it was the most convenient, in the circumstances of a college canteen random sampling would not of been sufficient as students would not want to wait to complete the experiment. The easiest and most reliable way of carrying out the experiment was for students in the canteen to be randomly asked if they wouldn’t mind spending a little time to take part in an experiment. They would leave the canteen and go into a quiet room to eliminate noise distractions and cheating, then they would be briefed and the experiment would begin. Stratified sampling would not of been as straight forward to carry out, and only 15 participants were needed so from a hall of at least 150, 15 is only 1/10th and chosen at random, the results are still very much valid.
TASK & MATERIALS
Choice of task was related to an interest in a previous experiment carried out in a class experiment, because it seemed like solid evidence that could be backed up by another piece of research carried out on a very similar format with the same principles, just a slightly different design. Materials used in this experiment were a stimulus sheet per participant per condition, A5 paper was used to save paper as all that was needed on the stimulus sheet was the 10 words to the start of each pair, and room for the participants to write their answers to complete each pair, and 30 stimulus sheets were needed. An example of stimuli 1 and 2 are shown on appendix 3 and 4. Black ink, capital letters, Times New Roman font size 12 was used, with a dotted line for participants to write their answers. This was the clearest way so participants did not need to ask where to write during the experiment, this could of altered their results due to different time length, and not understanding what to do causes confusion. Black ink pens were provided for participants to fill in the stimulus sheets, and the time given was strictly measured on a watch.
ETHICS
Firstly, every person approached in relation to the experiment was asked, “excuse me, could you spare a few minutes to participate in a simple psychology experiment?” everyone asked answered yes, they were then briefed on the experiment (appendix 1). The experiment had an element of deception involved, this was needed so participants did not alter their answers to fit what they guessed would improve their results. All participants were above 16, anyone below this age may not be mature enough to decide if they would like to participate or not, and could feel uncomfortable about withdrawing. 16 years and above gives you a better capability to decide this on your own. After the experiment all participants were fully debriefed to inform them what was being investigated, and to assure them once again that their answers remain anonymous and will not be used as data any further than this experiment. After participating in the experiment, everyone was asked to sign a participant consent form to show they agreed to taking part and were fully debriefed and understood the investigation. (Appendix 4).
PROCEDURE
All participants were approached in the main canteen at Truro College between 1 and 2 o’clock, which is the allocated lunch break. Each participant was asked, “excuse me, could spare a few minutes to participate in a simple psychology experiment?” No one answered no so they were all then asked if they wouldn’t mind coming into a quiet room so there is no noise distraction during the experiment. There was an empty classroom next door to the canteen, which could be used for the experiment.
15 participants were asked by the experimenter in the brief to remember 10 pairs of words and were given a stimulus sheet afterwards, with a list of the first 10 words to the pair. There was a 1 second gap between the paired words, and a 3 second gap between each pair, and a 30 second gap was given at the end before the experimenter gave out the stimulus sheets. The participant was instructed to recall the words they could remember in the correct spaces. After one minute these were collected back in. Immediately after they were given a quick re-cap brief for condition 2 and this was read out the same as condition 1. They were asked if they understood at different intervals. The second stimulus/response sheet was collected in.
Each participant was then debriefed, explaining what the experiment was investigating and reassuring them of anonymity and if they did not withdraw, asking for the last time if they wanted their results to be included in the experiment. They then signed the participant consent form (Appendix 4) but did not give their name as the experiment was anonymous and it was unnecessary information.
RESULTS
Raw data – My response/stimulus sheets can be found in Appendix 7.
Collated data tables – (Appendix 6)
The data collected was a score out of ten. This is interval level because the interval of the scale will always be a whole number, just like their scores, an all at an equal interval. For example, if they scored 8/10 and 7/10 it’s a difference of one, and if they scored 5/10 and 6/10 it’s a difference of one as well. This shows that the most appropriate measure of central tendency to use is the mean. There were no outliers in my results, it looks as though every participant did the best they could and all the results are satisfactory. However this may not be true, it is just a presumption.
A table to show the difference in mean and median between the number of words recalled during the first condition with the first list of words, and the second list with some differences and condition 1 acting as the proactive interference.
There is evidence of proactive interference shown in this table of results. The median is the same, because most of the participants in both conditions scored 10 out of 10. But the mean is higher in the first condition, this means more words were correctly recalled before proactive interference was added in the second condition to cause forgetting.
DISCUSSION
RESULTS RELATED TO HYPOTHESIS
The results from this experiment show the alternative hypothesis was retained. There was proactive interference taking place in the second condition, and this is the condition with a lower mean of words correctly recalled. This shows proactive interference did take place in condition 2. The alternative hypothesis being retained, means that in turn the null hypothesis is rejected, the results show proactive interference has taking place, so it did have a significant effect on the results.
RESULTS RELATED TO BACKGROUND RESEARCH
Comparing this experiments’ results to McGeoch’s 1942 study, they both found that proactive interference has a negative effect on memory recall.
LIMITATIONS
With every experiment, there are certain variables you cannot have control of. A laboratory experiment method was a good idea, but you can never have total control over all variables. The artificial conditions may cause unnatural behaviour, which means your results will lack ecological validity. To carry out an experiment in a laboratory it is more likely to involve deception because it is out of natural surroundings. Repeated measures were used and this was likely to cause problems with order effects. By condition 2 the participants had already heard some of the words once before and were likely to experience boredom, which decreases your concentration levels and would effect the experiments results. Demand characteristics may of become a problem, it is possible for the participants to work out what was being evaluated, but there was not a big element of deception involved, meaning if demand characteristics did take place, it wouldn’t make too much difference because there isn’t a lot for a participant to work out.
IMPROVEMENTS
Looking at the results, they do not differ much and therefore are not as valid as if they varied more. It would be a big improvement to change this and make the results more different so you could base stronger evidence on the results, this could be done by making the experiment harder. The results are all between 7 and 10, and there are so many participants who got 10 out of 10. If it was more challenging, perhaps there would be a bigger difference in their results and proactive interference would be more obvious.
This experiments’ results would have been more accurate and could of shown a higher effect of proactive interference if more participants were used because it increase the chances of mistakes being made and therefore the results would differ more. With only 15 participants it is not very accurate. The more people asked, the broader the prospective of the experiment, and therefore the more accurate the results are and the more they apply.
Asking a wider variety of people would have made the results more relevant to ‘people’ in general, as the research was not meant specifically for 16-19 year old students. This would give more accurate results and limit more extraneous variables.
FURTHER RESEARCH
There are lots of examples of proactive experience, that happen uncontrolled in everyday life. Every time someone learns something new, proactive interference can occur and they may have trouble learning a new skill because a memory of an old skill is getting in the way.
To extend this research another study of proactive interference should be carried out.
An example of this is learning how to play netball after playing basketball for a long time. When you learn netball, and you are thrown the ball, it is a similar memory of basketball and your memory will want to tell your body and muscles to bounce and run with the ball, which in netball are two rules already broken! It will take a while for your memory to separate the two skills, and then you will be able to identify the differences and perform both skills individually once netball is in your long term memory as well.
As an experiment, a basketball or netball team would be needed, make sure they do not have a familiar background with the opposite sport, and then teach them how to play the opposite sport, either netball or basketball
CONCLUSION
The results show a negative effect of proactive interference on the experimental condition 2. The aim was to carry out an experiment on participants to investigate proactive interference on memory recall. The hypothesis was one-tailed, based on McGeoch’s 1942 study of proactive interference on memory recall. The alternative hypothesis was that proactive interference will have a negative effect on memory recall of the word lists, and the null hypothesis was that proactive interference will make no significant difference on memory recall of the word lists. The results support this hypothesis well, but could be improved by a greater difference in the two conditions results of words recalled, this could be achieved by making both conditions harder, fir instance, doing 15 in stead of 10 words pairs so participants would find it harder to recall them. Overall this piece of research was successful, and it proved the alternative hypothesis to be retained.
REFERENCES
(The college of New Jersey)
(Use of)
APPENDICES
Appendix 1
Brief
Hello, my name is Rae Hamshire, and I am a psychology student at Truro College. I would like to carry out a short basic experiment and was hoping you would not mind participating. This experiment is confidential and you will remain anonymous. Before I continue I must ask for your consent to participate, this is not your final chance to back out, you can withdraw at any point you wish.
I am going to read out 10 pairs of words and I would like you to listen carefully, after I have read them I will give you a piece of paper with the first word from each pair on it, and ask you to recall and correctly match up the second word from each pair with the first. In the second part of my experiment I will read out 10 more pairs of words, the first being the same as before, and a different word for the second half of each pair.
You hold the right to withdraw at any point, so please feel free to say so. Do you have any questions?
Then I shall begin, I shall read the pairs 3 seconds apart, with a 1 second gap between the 2 words in a pair. After a 30 second rest I shall give you the stimulus sheet to write down your answers. You will have 1 minute.
Right, ready?
(Read out words of condition 1 and hand them the stimulus sheet).
Now I am going to read out the first 10 words to each pair again but with a different word to complete each pair. You will have another 30 seconds rest after I have read the 10 pairs out. Any questions? I shall begin now.
(Read condition 2 and give them stimulus sheet).
Appendix 2
Debrief
Thank you very much for taking part. I would like to assure you once again of the confidentiality of my experiment. My experiment was testing proactive interference on short-term memory. I wanted to see if you made any mistakes in the second list of word pairs due to the interference of the first list of word pairs. These two lists were my two conditions and condition 1 was used as a distraction from you correctly matching the words on the second list, which was condition 2. This was the only deception performed in the experiment, and was necessary for my results to be valid. I have hypothesized that proactive interference will take place, and more mistakes will be made in condition 2. If you have any further questions or concerns you can get in contact with any member of the psychology department at the college and if you would like to speak to me personally, they will refer you.
Stimuli sheet for condition 1
Dog………………………………..
Chair……………………………….
Banana……………………………..
Phone………………………………
Boat…………………………………
Wood……………………………….
Remote control……………………..
Picture………………………………
Purple……………………………….
Doctor……………………………….
Stimuli sheet for condition 2
Dog………………………………..
Chair……………………………….
Banana……………………………..
Phone………………………………
Boat…………………………………
Wood……………………………….
Remote control……………………..
Picture………………………………
Purple……………………………….
Doctor……………………………….
Appendix 5
Participant consent form
Signing this consent form means you agree that you gave your full consent to take part in this experiment and that you were fully debriefed afterwards.
Appendix 6
Data Table
Appendix 7
Raw Data
The raw data presented shows the 15 participants amount of recall in both conditions out of 10.
Condition 1 recalled words out of 10:
10 + 10 + 10 + 10 + 10 + 9 + 9 + 10 + 10 + 9 + 10 + 10 + 10 + 8 + 10 = 145/150
To find mean, divide by 15 = 9.67
As a percentage, 145 divided by 150 x 100 = 97%
Condition 2 recalled words out of 10:
9 + 10 + 10 + 9 + 10 + 9 + 8 + 10 + 10 + 9 + 10 + 9 + 10 + 7 + 10 = 140/150
To find mean, divide by 15 = 9.33
As a percentage, 140 divided by 150 x 100 = 93%
