Coding, Capacity and Duration of Memory Flashcards
What was Baddeley’s research on coding?
Baddeley gave different lists of words to 4 groups of participants to remember.
Group 1: words acoustically similar
Group 2: words acoustically dissimilar
Group 3: words semantically similar
Group 4: words semantically dissimilar
Participants were shown the words and asked to recall them in the correct order. When they did this from their STM, they did worse with acoustically similar words. When they did this from their LTM, they did worse with semantically similar words.
What were Baddeley’s findings on coding?
STM is coded acoustically and LTM is coded semantically.
Wat was Jacobs’ research on capacity?
Jacobs measured digit span to measure how much information the STM can hold. The researcher would read out 4 digits and the participant would recite them back in the correct order. This continues until the participant fails. He found that the mean span for digits was 9.3 items and for numbers was 7.3.
What was Miller’s research on memory and chunking?
Miller observed that things tend to come in sevens - deadly sins, days of the week, musical scales etc, and theorised that the capacity of STM is 7 +/-2 items.
What was Peterson & Peterson’s research on duration?
They conducted trigram experiments. Participants were given 3 letters to remember, and given a 3-digit number to count back from for either 3,6,9,12,15 or 18 seconds (the retention interval). After 3 seconds, avg recall was 80% but after 18 seconds, avg recall was 3%.
What were Peterson & Peterson’s findings?
STM duration was around 18 seconds, without rehearsal.
What was Bahrick’s research on duration?
He studied duration of LTM - he showed 392 American participants up to 74 years old their school yearbook. Recall was tested in photo-recognition, or free recall.
What were Bahrick’s findings?
Participants tested within 15 years of graduation were 90% accurate in photo recognition, and 70% after 48 years.
Free recall was 60% after 15 years and 30% after 48 years.
LTM may last up to a lifetime.
What is a strength of Baddeley’s research on coding?
Separate memory stores - identified a clear difference. The concept of STM using acoustic and LTM using semantic led later to the multi-store model.
What is a limitation of Baddeley’s research on coding?
Artificial stimuli - in real life something would have personal meaning to participants, so Baddeley’s findings may not tell us much about coding in different kinds of memory tasks, especially in everyday life. When processing more meaningful information, people may use semantic coding for STM tasks. This suggests the findings have limited application
What is a strength of Jacobs’ study on capacity?
It has been replicated - it is a very old study (1887) and early research lacked adequate controls - such as PPs being distracted. Despite this, Jacobs findings have been confirmed by other, better controlled studies. This suggests Jacob’s study is a valid test of digit span in STM.
What is a limitation of Miller’s research into memory and chunking?
Not so many chunks - Cowan reviewed the research and concluded that the capacity is more like 4 +/-1 chunks. This suggests the lower end of Millers estimate is more accurate.
What is a limitation of Peterson and Peterson’s study into the duration of STM?
Meaningless stimuli - the stimulus material was artificial, and the study is therefore irrelevant to most everyday memories wherein some of what we are trying to remember is meaningful. This lacks external validity.
What is a strength of Bahrick’s study into the duration of LTM?
High external validity - the researchers investigated meaningful memories, suggesting Bahrick’s findings offer a realistic estimate of the duration of LTM.
