The probability level of the results was analysed using the Mann Whitney test. The interval-scale data was collected and formulated into two tables of raw data (see appendix 7, 8). These comprised a table of scores relating to recall of words from the randomised list and recall of words form the hierarchical list. The scores were converted to ordinal- scale data and analysed using a two-tailed Mann-Whitney test (see appendix 9). The lowest value being rank 1 and the highest rank N. Ranks were shared for those who scored the same. U is the observed (i.e. the calculated) value of the Mann Whitney statistic.
The observed value of U at 0.05 level of probability was 54; the critical value was 37 (U= *, N1 = *, N2 = *p> or <0.05). It was therefore necessary to reject the research hypothesis. The results indicated a greater than 5% probability that the null hypothesis was correct and for this reason the null hypothesis was retained. Any difference in recall was purely due to chance. The experiment failed to provide significant evidence that word recall was improved through a hierarchically structured presentation.
The results demonstrated no significant difference in the number of words recalled across the two conditions. The two-tailed hypothesis was therefore rejected and a null hypothesis was retained. We were hoping for results that supported Bower’s study because his work was adopted as our model. There could have been a variety of reasons for why the experiment did not concur. Bower and Winenz suggested that if participants were asked to read out loud it would improve their recall ability. If we had applied this method then better results may have been achieved. The results may have failed to realise our expectations due to inherent errors in our approach. Perhaps choosing participants from our pier groups was a mistake. For a true insight into someone’s memory the participant has to be receptive at the time of testing.
The relaxed atmosphere that exists around friends and family may have had a negative effect on the participant’s concentration levels. The trials were supposed to be conducted as formally as possible but it would be hard to totally discount the fact that the participants may have been simply going through the motions. Would the results have been different if the same participants were used but in environment of say a job interview? Fatigue or a rushed approach of the participants may also have a played a factor- was the trials conducted straight after work? Late at night? Or while the participants mind was elsewhere?
Some of the participants may have a very high IQ others may be low. If we had more time the experiment could have been improved using a matched pairs design. This would have improved the subject variables and the consistency across the two conditions, therefore would produce more reliable results. Validity could also be subjected to the experimenter’s variables. I had no control over where and how the other experimenter’s applied their tests. It could have been a noisy room a television or radio may have been on in the background, or the participant may have talked through the experiment. To reduce the effects of extraneous and participant variables good sampling and good control measures are needed.
In addition, the results supported Atkinson and Shiffrons theory of the two distinct and separate memory stores and the existence of the rehearsal loop. The participants were given 60 seconds to learn the words, it is reasonable to assume that the acoustic rehearsal occurred and some of the words were transferred into the LTM. It would have been interesting to see what words all the participants had remembered, if the results showed that the items at the beginning and the end of the list were recalled more frequently it would have supported Glanzer and Cunitz. The items in the middle of the list would have been the poorest to recall. This is further evidence of the existence of separate memory stores.
Suggestions for further research on this subject may include an experiment based on Paivio’s original work. According to Paivio and Csapo (1973) free verbal recall is generally higher for items presented as pictures rather than just words. He required participants to encode words and pictures verbally. The results of these experiments yielded a higher recall of pictures rather than words. It would be interesting to see if visual aids could provide meaningful context and therefore aid learning. I would extend my research and conduct the experiment again but see if there is any difference between randomised words and pictures with words. This would support the theory that image and verbal codes are independent. The superiority of pictures in free recall can be explained by the duel-coding theory.
If the results were insignificant it is necessary to look at other theories of memory of memory recall. Collins and Loftus (1975) revised the idea of semantic hierarchies by proposing a network model that was interconnected in semantic clusters (see appendix 10). They assumed storage systems in computers might be similar to ones in humans. The models concepts are represented in nodes. Nodes are connected with other nodes via links. It is referred to as the semantic network. The strength of the links between the nodes depends on the semantic relatedness between them. For example BMW and car have a strong link, whereas BMW and banana have a weak link.
The notion of spreading activation refers to the process by which the activation of a given node also activates others to which it is linked. This could explain why the results were not significant in our research. Some participants may not be knowledgeable about geography and therefore the links to word association will be weak. If the list had been words that most people could relate to for example food the test may have gained more positive results. This has come under some criticism due to the problems defining attributes. There are too many concepts difficult to define. Consequently another idea was developed which is known as the schema theory.
This is based on the idea that knowledge is stored in the memory organised in a set of schemas. Each incorporates all the knowledge of a given type of object or event that we have acquired from past experience. They are linked together into related sets organized hierarchically. Schank and Abelson (1977) proposed people have scripts that are used in our comprehension of everyday events. Scripts represent knowledge about complex event sequences. They can be broken up into hierarchical organised scripts and subscripts. This again could show why our results are weak because if the participants have not acquired knowledge from a past experience in reference to countries there will be poor memory recall.
Memory is key to how we function and interact with our environment and those around us. Research into memory development is an important field. We are constantly bombarded with information and if we can learn to retain this information and recall efficiently then it would enhance us all. One day technological advances may allow us to see into the brain. A system may be developed to decode the millions of tiny electrical impulses that flash around our heads and reveal more to us than we were previously aware. However as technology advances the need to retain information is being taken away from us. Everything we need to know is just the click of a button away.
Computers are everywhere and accessing information is becoming easier all the time. Some people don’t even know their friend’s telephone numbers any more. It’s just scroll to name and dial. It is important that we don’t let this over reliance on technology to take over one of the primary functions of our minds therefore a balance needs to be kept to maintain a healthy and active mind.