Short term memory and long term memory. Features of each store: coding, capacity and duration

Research on coding:

Once information enters the memory system, it is stored in different formats depending on the memory store. The process of converting information from one form to another is known as coding. Alan Baddeley, 1996a 1966b, gave different lists to four groups of participants to remember.

• Group 1 - accoustically similar words - words sounding similar (i.e. cab, cat, can)
• Group 2 - accoustically dissimilar words - words sounding different (i.e. pit, few, cow)
• Group 3 - semantically similar words - words with similar meanings (i.e. great, large, big)
• Group 4 - semantically dissimiar words - words with different meanings (i.e. good, huge, hot)

Participants were shown the original words and asked to recall them in the correct order.  When they had to recall the words immediately (STM recall test) they tended to do worse with acoustically similar words. When testing recall after 20 minutes (LTM test), they did worse with semantically similar words, showing that the LTM is coded semantically.

Evaluation:

Atrificial Stimuli -

A criticism is that Baddeley used artificial stimuli rather than meaningful material. the word lists had no personal meaning to the participants meaning we should be cautious when generalising the findings to different kinds of memory task. for example, when processing more meaningful informaiton even the STM may code semantically. This suggests the findings may have limited applications.

Research on Capacity:

Digit Span -

Joseph Jacobs 1887 developped a technique to measure digit span. the researcher gives, for example, 4 digits and then the participant has to repeat them in the correct order out loud. if correct, the researcher reads out 5 digits and so on until the participant cannot recollect the order correctly. This determines the individual`s digit span. Jacobs found the mean span for digits across all participants was 9.3, while the mean span for letters was 7.3.

Span of Memory and Chunking -

Miller 1956 made observations of everyday practise and noticed things come in sevens: there are seven days of the week, seven deadly sins etc. this suggests that the span of the STM is about 7 items…