The words, or stimuli were developed between myself and my colleague, Nghia Ton. We wrote down words which we heard or saw most often over a few days. We then narrowed the list down until we had what we thought were very basic words which most people will have heard of or used. The distraction task was also developed between myself and Mr. Ton. Counting backwards seemed like a good idea as one would have to concentrate on it, so to make it a little harder we decided to count in fours from forty in reverse.
There were twenty subjects, ten male and ten female. Ten of these were from the home environment and ten from the college environment. All of them were between the ages of thirteen and twenty. This only represents an accurate sample of the younger generation for a purpose, this being that older generations tend not to have such a good level of recall due to their ages. The sample taken was opportunistic. This means that people who were in the right place at the right time were sampled. This is opposed to a random sampling when subjects are chosen from many different places at many different times.
Apparatus The stimulus materials consisted of word lists. The list for the control group is randomly organised. (see appendix I) The list for the experimental group is the same words as for the control group but organised (see appendix II) A stop watch was used to time the distraction tasks and learning times.
The subjects were given a set of standardised instructions (see appendix III) which stated that they were to receive a word list of fifteen words and allowed twenty seconds learn them. After this they were to be given a distraction task which was to count in fours in reverse from forty to one for forty seconds. Then a test of free recall was to be given. Following this a verbal debriefing was to be given (see appendix IV) which stated the aim of the study and the reason why the subjects were not fully told what the experiment entailed.
This being because fully informed consent would have lead to the subjects attempting to organise the word lists themselves. This is justified because the subjects did not come to any harm and were fully debriefed afterwards. The experiment(s) were to be conducted in a quiet room not containing any other stimuli which may aid the subjects recall. This is an attempt to control any extraneous variables.
The first thing to compare is the mean values of both of the conditions.(see appendix V) For the experimental condition the mean is 10. In the control it is 5.1. The mean for the experimental condition is nearly double that of the control condition, thus showing a significantly higher level of recall for the experimental condition, meaning that the alternative hypothesis seems to be correct. Table 1.3 shows the measures of tendency and dispersion. (see appendix V) In the control condition the mean is 10 and the median is 9.5. This shows that the mean has not been distorted by any anomalous results. However, the difference between the two is larger than that for the control condition, showing that a particular result may have been slightly anomalous.
The standard deviation for each condition is rather low, suggesting that all the results were around the mean value. The standard deviation for the control condition is higher than that of the experimental condition, this being due to the fact that some subjects may have automatically oganised the information themselves, thus leading to higher recall for some and not for others. Graph 1 shows the subject against the number of words recalled. Both conditions show a steady positive trend.
The control condition covers the larger range of words recalled and at subject 8 moves up by two words. This looks like a relatively sharp increase, but levels out in accordance to the other scores. The experimental condition climbs quite steeply and does not have as many plateaus as the control condition, showing a steeper positive trend. There are not any anomalous results contained within this graph.
I have decided to reject my null hypothesis and accept my alternative hypothesis. Meaning that recall for the subjects which learnt the organised word lists was higher than that of the subjects that learnt the same word list but randomised. This is because the results for the experimental group are much higher than that of the control group. The results for the experimental group cannot be due to the subjects being better at remembering as the subjects were randomly allocated to each condition.
My experiment supports Bower et als experiment in so far as to say that semantic organisation of information does aid recall in the short term memory. However, as previously stated, the results may have been altered by the individuals ability to recall information. This is said to be a random error. It is not a confounding variable which is an uncontrolled constant random error which result in anomalous results.
Validity of a psychological measure is the extent to which it does measure what it is intended to measure. Therefore, was this experiment actually measuring memory or was it measuring the subjects word knowledge or reading ability? To answer this, one must look at the word lists. (see appendix I) The words are very basic everyday objects/actions, therefore I would expect that all of the subjects were familiar with them. Therefore, this experiment was a good test of memory with a high resemblance to how memory is used in real life.
However, I could have used items that are usually found on a shopping list, therefore increasing the resemblance to how memory is used in real life. I believe that my study is valid but could be improved as mentioned above. To ensure that the results from this experiment were reliable, I ensured that standardised instructions, procedure and stimulus materials were used. Standardisation means that all of the subjects receive exactly the same material. Meaning that no subject has a more ‘in depth’ instruction than the next. If one did this would confound the results.
I could have improved the reliability of the results by using one experimenter instead of two, thus reducing room for error in delivery of the oral debriefing and replication of the study. Due to my results supporting Bower et als experiment, it shows consistency. This proves that the theory of semantic organisation of information leading to higher recall is a reliable finding. My sample is an attempt at an accurate representation of the population, therefore my results should be able to be generalised to the public. However, my sample is opportunistic, this means that questions will be raised as to whether my sample is representative of the population. believe I achieved this by choosing equal numbers of male and female and equal. numbers from the home and college environment. Therefore varying levels of intelligence, ability and knowledge.
The experiment was a field study. Therefore subjects were in their natural setting, not a controlled laboratory. Also, the subjects knew me and so did not behave in an abnormal way which would affect the validity. I believe this experiment has a very high ecological validity due to this and the fact that the test had high resemblance to how memory is used in real life. In conclusion, I believe that my experiment was a valid and reliable look into the effect of semantic organisation on recall in the short term memory. It could have been improved though, as previously mentioned. My experiment supports the findings of Bower et al (1969) and I believe that conclusions can be drawn from my results as were from Bower’s experiment.
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