Coding, capacity and duration of memory Flashcards
coding
Coding is how information is stored
who researched coding
Baddeley
what was Baddeley’s research on coding
Baddeley gave 4 groups each a different word list to remember. The word lists were either acoustically similar or different or semantically similar or different. When recalling immediately after, the p’s did worse on acoustically similar words. When recalling 20 minutes after, the p’s did worse on semantically similar words.
These findings suggest that info is coded acoustically in STM and semantically in LTM.
evaluation of research on coding
Strength – identified a clear difference between two memory stores which was an important step in our understanding of the memory system
Weakness – used artificial stimuli, so Baddeley’s findings may not tell us much about coding in different kind of memory tasks in everyday life which suggests the findings from this study have limited application.
capacity
Capacity is how much information can be stored.
who researched capacity
Jacobs
Miller
what was Jacobs research on capacity
Jacobs found out by measuring digit span. He read out four digits and p had to recall immediately. If correct, he reads out five digits and this is done until the p cannot recall the order correctly, indicating the p’s digit span. Mean span for digits was 9.3 items. Mean span for letters was 7.3 items
what was Millers research on capacity
Miller thought capacity of STM is about 7 items, plus or minus 2 after noting that things come in sevens. But he also noted that people can recall 5 words as easily as 5 letters and this is done by chunking
evaluation of research on capacity
Strength – Jacob’s study has been replicated. Jacob’s study is an old study so may have lacked control however the results have been confirmed by other better controlled studies. Suggesting Jacobs’ study is a valid test of digit span in STM.
Weakness – Miller may have overestimated STM capacity. Cowan has contradicting research that suggests we can only remember 4 chunks. Limiting validity of Miller’s study.
duration
Duration is how long info can be stored for.
who researched duration
Peterson and Peterson
Bahrick et al
what was Peterson and Petersons research on duration
Research for duration of STM. Tested 24 students. All given a trigram (e.g. YNF) and had to count back from a 3 digit number for 3, 6, 9, 12, 15 or 18 seconds to prevent mental rehearsal. Recall was 80% after 3 seconds but 3% after 18 seconds. Suggests STM duration is about 18 seconds unless we repeat the information over and over.
what was Bahrick et al’s research on duration
Research for duration of LTM. Tested memory of classmates aged 17-74 through face-recognition or free recall of their classmates. In face recognition, recall was 90% accurate within 15 years of graduation and 70% accurate after 48 years. In free recall, recall was 60% accurate within 15 years of graduation and 30% after 48 years. Suggests LTM may last up to a lifetime.
evaluation of research on duration
Strength – Bahrick et al’s study has high external validity as researcher investigated meaningful memories. Suggesting Bahrick et al’s findings reflect a more real estimate of duration of LTM.
Weakness – Peterson and Peterson’s study had meaningless, artificial stimuli. So doesn’t reflect everyday memory activities. Therefore the study lacks external validity.
