The Man Whitney U test showed that UA was 23 and UB was 77. The smallest of these value becomes U and so the observed value was U 23. The critical value of U at the 0.05 level of significance on a two-tailed test is 23. The U is equal to this level and so is significant. The statistical test shows that the experimental group recalled significantly more words than the control group. A significance level of p< 0.
05 was used because it is the most conventional significance level. At this level the chance that the null hypothesis will be retained and that there will be no real difference between groups under these conditions is about one in twenty. Therefore there is a possibility that the results were obtained by chance.
The null hypothesis can be rejected and therefore the alternative hypothesis is retained. There is never certainty about whether the results were simply a fluke and so a type one error may have occurred. This means that a mistake may have been made in rejecting the null hypothesis when it is true. Variations in the results may have been caused by random variables.
Discussion After performing my experiment, researching how the Loci method of recalling data affected the recall of a word list, I found that my results supported all the previous research I had looked into. They showed that memory was improved with the aid of mnemonic devices.Firstly, Bower’s study, which found that in the recall test those who used mnemonics remembered 72% of the items while the non-mnemonic group only averaged 28% recall. Although his experiment used 5 word lists each containing 20 words and in this experiment only 1 list of 10 words was used, the findings were similar to Bower’s.
Secondly, Luria’s experiment (1968) which studied a Russian reporter Sherehevski who was able to recall strings of words up to fifty words in length after hearing them just once.He associated each item with a visual image on a street in Moscow. When recalling the list he would take a mental ‘walk’ down this street and would recall each item as he passed it.
Sherehevski used the Loci method as the experimental group did here – and the results in this experiment show that his method works better than recalling without any mnemonic devices. The difference however was that Luria’s subject could recall up to 50 words at a time, obviously way above the number available here.Baddeley’s experiment in which he gave one group a list of words and asked them to recall them straight after learning, and gave another group a 30 second delay after learning. He found that recency effects were eliminated after the 30 second delay. In this experiment, there were signs of recency effects with some participants remembering the last 3 words (recency effect) and some remembering the first 3 words (primacy effect).This experiment had an unrepresentative sample – only participants aged 16-18 were used and all were from similar educational backgrounds.
The experiment could be improved by using a few different methods. One could have selected a target population that included people without any educational background (and so would be unused to learning rules) and one could choose participants from different age groups.Also, the sampling method used was not random so there would definitely an element of bias in the sample chosen. A computer could have selected participants randomly but this would not be necessary in a study of such a small scale. As in Bower’s study, the word lists could have been longer (20 words or more) and there could have been more of them (Bower used 5 lists). In this study, with only 10 words in the list, participants would be able to memorise the words without using the mnemonic device.
Longer word lists would have made it more difficult for the participants to use repetition to recall the items. In addition, the interference task may not have been effective enough as recency effect was still present, as mentioned above.This experiment could be used both in everyday life (e.
g. remembering shopping lists) and in medical cases (e.g. Amnesiacs or sufferers of brain trauma) to aid memory and in the case of Amnesia, to slowly reconstruct the client’s memory.
Further to this study, one could research the gender differences in depth regarding mnemonic aids in memory. Also, one could study the effects of mnemonics across different cultures. This would help as different things can be thought of in different ways by different cultures e.g. the items on the word list or the places in the Loci method may mean something to one culture but mean nothing to another culture.