Outline and evaluate the multi-store model of memory.

There is a lot of evidence to suggest that there are in fact three memory stores. Capacity differs greatly between long term and short term memory. In Jacobs' study into span measures and capacity, he found that when he presented participants with a sequence of numbers and letters, to be recalled immediately after presentation, they could only recall 5-9 items. Therefore, the capacity of short term memory is 5-9 items. We can, however, continue to store things within our memories over the course of our lives, suggesting that the long term memory has an unlimited capacity. This gives valid evidence that there are separate memory stores.

Further evidence for separate stores can be seen in Baddeley's study into the encoding of both long term and short term memory. Baddeley found that short term memory encodes information acoustically and that long term memory encodes semantically. He presented participants with four sets of different words - Set A (acoustically similar), Set B (acoustically dissimilar), Set C (semantically similar) and Set D (semantically dissimilar). By splitting the participants up into two groups, he was able to make some participants use their short term memories by asking them to recall the sets immediately after presentation, and the rest were to use their long term memories by having a timed delay between presentation and recall. His findings show that participants using short term memory recalled Set A well and Set B least well. However, participants using long term memory performed equally as well on both Sets A and B. This once again suggests that there are separate stores.

The final way in which evidence can be given to support the multi-store model is the duration of the long term and short term memory stores. Peterson and Peterson found that short term memory has duration of 18 seconds. They found this by presenting participants with trigrams which they were to recall after 3, 6, 9, 12, 15 and 18 seconds after 18 seconds, only 10% of the trigrams could be recalled, showing that the duration of short term memory is 18 seconds.

Bahrick's study proved that the duration of long term memory is different. He discovered this through American ex high school students being tested on who they could remember from their school days. His findings show that most ex students were 90% accurate when doing face and name recognition. Older participants weren't as accurate with 80% for name recognition and 40% for face recognition. This does, however, show that although the memory, may fade with age, it does still carry information for a long time.