There are 3 concepts of interference:
-
Transfer → information from the past
-
Retroactive → existing memories are corrupted by the learning of new material
-
Proactive → new material is corrupted by existing memories.
The first concept is transfer. After some early point in life, people rarely, if ever, learn anything that is entirely new. Rather, people bring to any "new" learning of knowledge or skills an accumulation of related knowledge, skills, and habits from the past. Such prior learning influences the qualitative and quantitative character of the new learning process. Such transfer effects may be positive or negative, depending on whether prior experiences facilitate or impair the new learning process.
The second concept is retroactive interference. Whereas transfer refers to the effect of earlier learning on later learning, retroaction refers the impact of interpolated (intervening) learning experiences on one's memory for something teamed earlier. Once again, such effects may be positive or negative (retro-active facilitation and interference, respectively), depending on the similarity of the original and interpolated learning tasks. It is the negative case—where retroactive interference causes forgetting—that applies to this discussion. Thus, if one's ability to recall the maiden name of a woman is impaired by virtue of having learned her name, one is suffering from retroactive interference.
The third is proactive interference. Something learned earlier may also impair one's ability to recall something learned more recently. If, for example, one is less able to recall a woman friend's married name by virtue of having learned her maiden name at an earlier time, one is suffering from proactive interference
I will be testing retroactive interference. Participants will be given a list of 20words to learn. After this they then will be doing an activity, which requires thought and concentration. The activity should therefore interfere with the memory of the words and affect the recall.
Aim
To investigate whether or not interference has an affect on the recall of words.
Experimental Hypothesis
Participants who experience interference will recall fewer words than the participants who do not experience interference. One tailed hypothesis.
Null Hypothesis
Interference will have or no effect on the correct recall of words.
Design
The independent variable in this experiment is whether interference is experienced. The interference its self is to count back in two’s from 60. The group which do not experience interference will not have to count back they will immediately recall the words after the 60 seconds they have to rehearse them. The dependant variable will be how many words are recalled successfully in each group.
Extraneous variables in this experiment could cause unreliable results. One example is the environment in which the experiment is set. This could affect results as if the participants are too hot, too cold or put off by the noise around them it will put them at an unfair disadvantage as it is likely for them to put less concentration into the experiment and more concentration into what is going on around them. To over come this problem the experiment will be set in the un-used library. They’re will be no noise and will try to keep the temperature in the room constant and make sure no one is likely to open the door and disrupted the experiment.
Another extraneous variable are the instructions the participants are given. If some one is sat at the back of the room and can not hear the instruction clearly or is not really sure on what to do this will also put them at an unfair disadvantage as they will not be able to work to their full potential if they are not sure on what they are doing. To overcome this a printed set of instruction (appendix 4 + 5) was given to each participant and made sure they were precise and clear to follow and before the experiment started. It was asked if every one knew exactly what they were doing and if they had any questions they would like to ask before the experiment got underway.
A few other extraneous variables are the time of day as if it is too earlier or too late the participants maybe tired and not able to perform to the best of their ability. Age is an extraneous variable as if the participants are under 16 then would need written consent from parents and at different ages there abilities will be different older ones normally with more knowledge than younger ones. Gender is one too as many experiments have been judged on gender; boys smarter than girls and the other way round. Realistically this shouldn’t be an issue as the experiment looks at interference not gender or age as some research suggests.
This experiment has an unrelated design. Participants in each group are selected at random and different in both groups. This has advantages for the experiment. It will eliminate factors such as tiredness, boredom and practice as no one participant will be doing the same experiment more than once. Therefore no one is at an unfair advantage. Another advantage is that it is economical as the materials used can be reused with each experiment and the two conditions. Unrelated design also helps to reduce any demanding characteristics, being that participants will have little chance of finding out what the experiment is about from other participants.
******* ETHICAL ISSUES FRM SKWL!
Participants
The target population for this experiment was the 6th Form students of Campsmount Technology College in Doncaster. The age ranged from 16-18years in both groups. Therefore had to make sure there was a range of these ages in both groups. As if one group contained more older people than younger than there results are likely to be slightly higher than the group with more younger people in but this should not be an issue as the experiment is not based on age.
The groups contained 20 students of mixed genders (10 in each group). There was no need for the same amount of males and females, as the experiment was not based on gender.
Opportunity sampling was used to choose participants. This was used as it had an advantage of being an easy way of gathering data from the participants who wanted to take part in the experiment but it is not fairly representative of the target population.
Materials
The materials used for this experiment consisted of: a list of 20 random words which were not to easy or difficult to recall, the font size was 18 in the color of black, they were printed on a plain sheet of A4 and in the typing of Comic Sans MS as it is easy to read and consistent (appendix 1). 20 answers sheets were need for the participants to recall the words (appendix 2) and a pen to write them down. A set of instructions for the 2 different experiments (appendix 4 and 5) was needed so the participants knew exactly what they were doing for both experiments. A brief (appendix 3) to explain who I am and why I need to do the experiment and for the participants to give consent and debrief (appendix 6) to state the aim and explain what both groups had just done, also to ask permission to use the results had been gathered and tell them they were to be kept anonymous. A stop watch to time the participants whilst they looked at the words and then needed again when they recalled them. Also in experiment 2 it was needed whilst they counted back in two’s for a period of time. This has to be precise so the participants only experience interference for the set amount of time and so they don’t have any longer to read the words than allotted.
Procedure
Firstly to gather the groups of participants that were to be used a sheet was put up in the common room where most of the 6th form group study and ask for volunteers. Those who were willing to participate were then approached individually and told to meet in the 6th form library at 1:00pm and this is where the experiment was to be conducted. They were then reassured about the experiment and given a briefing which explained the situation - Hello my name is Amy Kelleher I am a currently a 6th form student doing my AS psychology. This course involves me doing a piece of course work
As part of this course work I am doing this experiment to test a theory, which we have studied in class. I have chosen to study interference and this is where you come in. I would like you to memorize a list of 20 words. In the debriefing I will explain my purpose. I will answer any question you may have. All your results will remain confidential and you have the right to withdraw at any time. Now I would like to ask if you would continue with the experiment? -. After everybody had gave consent a full set of instructions were given to each participant so that they would feel confident about what they was about to do (appendix 4) and answered any questions what they might have.
A sheet of A4 paper which contained the 20words (appendix 1) was issued and placed face down so that they would not have any longer than the allotted amount of time to study the words which will be measured using a stop watch. Next the answer sheet was to be issued (appendix 2). This had no writing on except the numbers 1 – 20 down the left hand side with enough space for the participants to write down there answers. After a pen was issued the group was instructed to turn over their list of 20words and begin. At this point the stopwatch was started. The participants had 60 seconds to study and remember as many words as possible. After this time was up the list of words was taken (appendix 1), reset the stopwatch and instructed them to write down as many answers as they could remember on the answer sheet (appendix 2) and gave them 30seconds to do so.
However, for group 2 the procedure differs at this point. After the list of words had been taken (appendix 1) and reset the stopwatch I instructed the participants to count back in 2’s from 60 for 30seconds. This ensured group 2 experienced interference and a clear comparison of the results could be made. After this 30seconds was up, the stopwatch was reset and instructed the participants to write down as many words as they could remember on the answer sheet (appendix 2)
All participants were full debriefed - Thank you for taking part in my experiment. The aim of this experiment was to see if interference had an effect on the recall of words. This experiment needed two groups of people. The first group was given the list of 20 words a 60 seconds to rehearse just as the second group was. The first group were then given 30 seconds to recall all the words they could remember. Group 2 however first had 30 seconds to count back from 60 in two’s until the 30 seconds were up then they had to recall the words. By doing this they experiencing interference. I will compare the results from each group and see if interference has an affect on the recall of words. All personal information will remain confidential and I now need your permission to use your results in my coursework but keep all names confidential? -.
Pilot Study
In order for the experiment to be fully effective a pilot study had to be carried out, its purpose was to see if any improvements could be made from my initial idea’s and that the method could run smoothly and no problems would be experienced. A list of 15 words was issued. Participants had 60 seconds to rehearse the words before recalling them for the duration on 30 seconds. The second group was tested in the same way except they were to experience interference, after they had had 60 seconds to rehearse the 15 words the had to count back from 6o in three’s for the duration on 30 seconds then recall the words for another 30 seconds. There were 5 people in each group adding up to 10 and these people were not used in the proper experiment as they would no exactly what the experiment was about and it would put them at an unfair advantage.
Pilot Study Results
After conducting the pilot study there had to be a few minor changes. Firstly the instruction needed to be clearly as some participants got confused and started to recall the words on the back of the sheet before instructed and a number of people was asking where they wrote their answers. Secondly my interference proved to be slightly to difficult and some participants were getting really confused counting back in three’s and this affected their maximum performance. For the real experiment the interference will be changed from counting back in three’s from 60 to counting back in two’s and the time scale will stay the same. Thirdly the number of people in each group is going to change to 10, this will maximize the results and change the number of words from 15 to 20.
Summary Of Results
The measures of central tendency and measures of dispersion are show below for both the interference and non-interference groups.
Raw Data is shown in appendix 7 and 8
From the table it can be seen that the average number of words recalled for no interference is 13.7, which is approximate 3-4 higher than the number of words recalled with interference. The median is also higher in the no interference group (14) than the interference group (8). This result initially supports the experimental hypothesis at the start- Participants who experience interference will recall fewer words than the participants who do not experience interference-. The bar chart shows a higher average number of words recalled in the no interference group and the line chart also illustrates that a higher average number of words were recalled with no interference compared with interference. The standard deviation for the no interference group was 1.836 and for interference it was 2.855. This indicates that interference does affect the recall of words and results in less words being remembered. Therefore the experimental hypothesis is accepted and the null hypothesis is rejected.
Discussion
From the results we can see that the mean number of words recalled in group one who did not experience interference was 13.7 this is significantly higher than group two’s mean of 9.1 as they did experience interference. The median was also higher in the group that did not experience interference compared with group two’s. The mode for group one who did not experience interference was 14 and groups two’s mode that did experience interference was 8. This also provides evidence to support the fact that experiencing interference makes you remember fewer words. The standard deviation shows the distribution of all the scores. It is useful as in takes every score into account it gives us an indication on the scores vary from the mean. The standard deviation for group one with no interference was 1.836. This was lower than group two’s standard deviation, which is 2.855. The lower the score for group one (no interference) shows that the scores occur closer our mean than those of group two (interference). Therefore the score of 2.855 shows that the scores were not as close to the mean as group ones were. Which means these results for group two are not as consistent as group one’s results. Both the charts show a higher average number of words recalled for group one (no interference) than group two (interference). All these results support my experimental hypothesis - Participants who experience interference will recall fewer words than the participants who do not experience interference -. This means the null hypothesis can be rejected and we accept the experimental hypothesis.
In Jenkins and Dallenbach (1924) study the length of time in which the participants had to learnt the words and when they recalled them was the same but one had experienced interference as they had done it in the day and the daily tasks had interfered with the information but the other participant did it at night and went to sleep. The participant who did it at night remembered more, in the experiment I conducted the amount of time participants had to learn the words and recall them was exactly the same just group two hade experienced a form of interference which made them recall lest words. This means the results support the theory of interference as well as Jenkins and Dallenbach. Also Baddeley (1997) experiment showed that it did not matter how much time had elapsed it was the number of games played which effected recall. As the times in my experiment were the same and the only changed was the interference experienced then this was the only factor that could have affected the results.
Limitation could have affected this experiment, which would of lead to unreliable results. One of these was the sampling method chosen. Opportunity sampling produces a biased sample and is nor representative of the target population, which means you, cannot generalize the results. A stratified sample would overcome this problem. This method list variables, which could affect the experiment, and takes them all into account. This is a very time consuming process so is not often used and also it isn’t cost effective.
Another limitation is the design. Unrelated design does not take into account the differences of participants such as ability and intelligence this too would make the results biased. If there is a significant difference in the two groups it could be due to ability. A way of reducing this is matched pairs design where participants are matched together by a certain characteristic e.g. intelligence, gender or age. You can find people like this through surveys and questionnaires.
The time of day could have been an extraneous variable but this was kept the same it every experiment. By doing this it helps keep the experiment constant and reliable. The experiment was held at lunchtime, which was 1:00pm giving participants time for to have their dinner. This is one of the best times to hold an experiment, as the participants would be awake and concentrating. They would also have had their dinner so not have hunger putting them off which helps them perform to the best of their ability.
An ethical issue, which was present during my experiment, was deception. The participants were not told the full aim and purpose of the experiment until they had completed it as it may have made the results unreliable. At the end of the experiment the full purpose was stated in the de-brief and they were made aware that they could still withdraw their results at any time.
the experiment could have been improved by repeating it, to make sure the results were consistent every time and no anomalies would be present. The sample could be to gain more reliable results and the interference could be made easier to see if it still affected the recall of words this would also help to obtain more reliable results.
The experiment could also be investigated into different areas such as age, gender, ability, social class and race. For example tested whether or not interference affects recall more in males or females. There would have to be two groups, one all girls and one all boys, for interference and two groups for no interference again one all girls and one all boys. And all of the others could be investigated in the same method as above.
In conclusion my experimental hypothesis was correct; interference does affect the recall of words and results in fewer words being successfully recalled.
Bibliography.
- Cox.E, 2002, AS level psychology for AQA, specification B.
- Cox.E, 2001, psychology for A. level
- Baddeley.A, 2003, human memory, theory and practice, revised edition.
“An Investigation looking at the affect of interference on the recall of words.”
