Craik and Lockhart's Theory on Memory

Abstract

Craik and Lockhart (1972) proposed that it is the method and depth of processing affects how an experience is stored in memory, rather than rehearsal. To determine the level of processing between semantic and phonemic encoding, 26 word pairs was shown to 837 undergraduates and each participant has 30 seconds to determine whether it was a category association or rhyming relationship. The participants were then asked to recall and associate the given word pairs. As hypothesized, category condition presented deeper processing and yields greater retention. Implications for further research are discussed, particularly with respect to encoding process, the greater specification on concept of depth.

Depth of processing: Effects of semantic and phonemic encoding.

Many experiments have been performed on depth of processing and the model of memory states that information is encoded into a person’s memory depending on the various levels of processing. Craik and Tulving (1975) carried out a series of experiments on the depth of processing model using variation methods of processing to encode words at superficial, moderate, and deep levels. A sequence of words was shown and questions that consist of a yes or no response were asked. Participants were being questioned whether or not the word was written in capital letters at the superficial level. At the moderate level of processing, the participants had to determine whether the words were rhymed. Finally at the deep level of processing, the participants were asked about words in sentences and whether they belonged to the same category. At the end of the task, a surprise recognition test was given to the participants, which incorporated words that were asked earlier and words that had never appeared on the list. The results showed that deeper level of processing was required to remember words better.

Palmere, Benton, Glover, and Ronning (1983) perform a range of experiments elaborating on the level of processing model with paragraphs includes supporting sentences and those that were not. After reading through all the paragraphs, participants were given a recognition test. The results of this experiment showed that greater information about the sentences associated with other information were retained. These substantiate the level of processing model because information were retained and encoded at deeper level when the information had more detail that induces thinking.

Cermak (1972), Craik and Lockhart (1972), Hyde and Jenkins (1969, 1973) summaries a range of alternative approach to study processes more directly which involve recollection such as attention, rehearsal, encoding and retrieval and to devise a representation system of memory.

Similar results have been reported for the retention of sentences (Bobrow & Bower, 1969; Rosenberg & Schiller, 1971; Treisman & Tuxworth, 1974) and in memory for faces (Bower & Karlin, 1974). In all these experiments, participants are required to determine whether semantic judgments or structural judgments led to better memory performance.

This study aimed to determine whether the participants made a semantic or phonemic decision at the encoding stage. According to the information-processing model of memory, which incorporates the level of processing view of encoding by Miller (1956) states that deeper levels of processing will generate greater recollection. Thus, I predict there will be better actual recall in the category group as compared to those in the rhyme group. It was also hypothesized that most people will not recognize the effects that levels of processing has on their recall performance and people tends to overestimate their actual capability generally. It was expected that estimates of recall performance would be higher than actual recall performance and there would be no significant difference in the estimates of recall performance for the two conditions.

Methods

Participants

A total of 837 undergraduate students from an introductory psychology class at University of Western Australia performed the experiment as a laboratory exercise. No account was taken of age and gender.

Apparatus

The experimental list was presented on a DELL Personal Computer, which scored participants’ responses and percentage of estimation.

Procedure

Participants received instructions in responding and they had 30 seconds to determine each pair’s category association or rhyming relationship. Participants responded to a 6-item trial list before attempting the experimental list. Word pairs in the trial list were identical for all participants and the nature of trial list was corresponding to the experimental list.

Participants tossed a coin to decide on which condition they will be tested before initiated the experimental list. Head of coin indicates category condition and tail of coin indicates rhyming condition. Followed by recording their percentage of estimation prediction that they were able to recall, and clicking on the “START” button to commence.

26 word pairs were shown and participants must decide whether the two word pair has the same (rhyming) sound or different (non-rhyming) sounds. Participants will then respond by clicking on either the “SAME” or “DIFFERENT” button.

In the second phase of the experiment, one of the words from each of the pairs presented earlier on will be shown and participants will have to recall and type in the other word from the same pair. Participants will make a best guess if they are not able to recall the associating word. There are no time limits associated to each question.

Results

         Descriptive statistics summarizing the semantic and phonemic encoding condition are shown in Table 1. The mean, standard deviation and Cohen’s d for semantic and phonemic were calculated as a function of recall. The results are shown in Table 1. Mean semantic ratings were significantly higher for participants in the estimated recall group relative to participants in the actual recall group. Similarly, scores on the test of phonemic were significantly higher for the estimated recall group compared to the actual recall group. By contrast, the mean of actual recall on semantic condition is higher than phonemic condition. Taken together, these results suggest that semantic encoding is more effective in retention of words as compared to phonemic condition. There was no strong difference between the estimates of recall performance for the two conditions.

         Correlations between the measures for the whole sample are presented in Table 2. The estimated recall has a higher mean then the actual recall. Relative to the variability (standard deviation) in the scores obtained was relatively small for the whole sample.

Discussion

        The current study aimed to examine whether semantic or phonemic encoding is more effective in retention of words. As hypothesized, the semantic condition had better retention of words then those in the phonemic condition. It was also hypothesized that there would be no difference in the estimates of recall performance for the two conditions and people tends to overestimates their actual abilities. Two of the three hypotheses were supported.

        The findings that deeper semantic processing yields superior retention were consistent with Craik and Lockhart (1972) results, supporting the proposition that levels of processing are an important determinant of retention for word events. Specifically, Moscovitch and Craik (1976) showed that cued recall was better when the target items had been presented in a category judgment. Therefore, memory is enhanced when deeper processing of the stimulus is required at learning.

The finding that participants were poor at predicting their own performance extended Kruger and Dunning (1999) contention that individuals tend to overestimate their own level of skill.

The experiments reported in Craik and Tulving (1975) shows that one of the implications is when people are given instructions to learn, they do not learn best. The nature of learning process may be further exposed by comparing performances under learn instructions against performance of incidental tasks with various combinations.

To substantiate that semantic encoding influences deeper processing, research should thus counterbalance a more objective, measurable, index of concept on depth and consider the language proficiency of the participants.

Future research should explore issues on different sensory modes as they involve different depths of processing, generally producing higher recall value in certain senses than others.

The current study does suggest that it would be worthwhile to extend this research by identifying the similarities and differences between encoding and retrieval processes. In summary, this study showed that deep semantic processing led to better recall than shallow phonemic encoding. These findings suggest that good explicit memory performance related to deep semantic processing is undeniable.

References

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