Research Into Coding, Capacity And Duration Flashcards
Research of duration of stm
PETERSON AND PETERSON 1959
- read nonsense syllables to p’s and got them them to count backwards in 3’s from a large 3 digit number
- each p had 8 trials, on each trial the time spent counting backwards was different
- 80% of nonsense syllables were recalled correctly after 3 seconds
- 3-5% after 18 seconds (suggests STM has a duration of 18-30 seconds)
What type of experiment was Peterson and Petersons research and what was the variables?
Lab
IV= TIME INTERVAL between hearing the experimenter say the trigram and the p repeating it
DV- NO OF TRIGRAMS CORRECTLY RECALLED
Aim of Peterson and Petersons research
To investigate the duration of stm memory and provide evidence for the multi store model
Limitation - PETERSON + PETERSONS STUDY WAS ARTIFICIAL
P - stimulus material was artificial
E - trying to memorise trigrams doesn’t reflect real life memory activities so the study LACKS EXTERNAL VALIDITY
I&D - research explaining the msm is an example of experimental reductionism as it attempts to explain complex behaviour by relying on isolated variables which is argued to undermine the complexity of human memory
C - however study isn’t totally irrelevant as we try to remember meaningless data such as phone numbers
Research on duration of ltm
BAHRICK ET AL 1975
- showed 392 p’s aged between 17-74 a set of photos and list of names (some were ex school friends)
- photo recognition test + free recall
- p’s tested within 14 years of graduation were 90% accurate in photo recognition. After 47 years, recall declined to 60%
- FREE RECALL NOT AS GOOD AS PHOTO RECOGNITION. After 15 years this was 60% accurate, dropping to 30% after 48 years
What type of experiment was Bahricks research and what was the variables?
Field (longitudinal study)
IV= photo recognition/free recall
DV= correctly recalled/matched names and faces
Aim of Bahricks study
To investigate peoples ability to recall and recognise names and faces over time
Strength - BAHRICKS STUDY HAS HIGH EXTERNAL VALIDITY
P - Bahricks study has high external validity
E - real life meaningful memories were studied. When ltm studies have used meaningless pictures, recall rates were lower
C - Bahricks research was a field experiment so there was a lack of control over confounding variables (p’s looking at yearbook photos and rehearsing their memory)
Research on coding
BADDELEY 1966
- gave different lists of words to 4 groups of p’s
1. Acoustically similar
2. Acoustically dissimilar
3. Semantically similar
4. Semantically dissimilar - when they did the recall task IMMEDIATELY after hearing the words they did worse with ACOUSTICALLY SIMILAR WORDS (info is coded acoustically in stm)
- when they did the recall task after a TIME INTERVAL OF 20 SECONDS they did worse with SEMANTICALLY SIMILAR WORDS (info is coded semantically in ltm)
What type of experiment was Baddeleys research and what was the variables?
Lab
IV= similarity of info and time interval between recall
DV= correctly recalled words
Aim of Baddeleys research
To investigate whether stm and ltm encode info in different ways
Limitation - BADDELEYS STUDY USED ARTIFICAL STIMULI
P - used artificial stimuli rather than meaningful material
E - word list has no personal meaning to p’s so we should be cautious about generalising the findings to other memory tasks
C - suggests the findings have limited application
Counter argument - lab experiments have higher control over extraneous and confounding variables
Research on capacity
JACOBS 1887
- developed a technique to measure digit span where the researcher gives a certain amount of digits and the p is asked to recall these
- if this is correct the researcher reads more digits until the p cant recall these order correctly (this determines the individuals digit span)
- mean span for digits was 9.3 items, mean span for letters was 7.3 items
What type of experiment was Jacob’s research and what was the variables?
Lab
IV= stimulus type
DV= span size and span total
Aim of Jacob’s research
To investigate the capacity of stm for numbers and letters
Limitation - JACOBS STUDY CONDUCTED A LONG TIME AGO
P - conducted a long time ago
E - early research in psychology lacked control so p’s may have been distracted (extraneous variables)
C - results may not be valid as there were also confounding variables. However, the results have been confirmed in other research, supporting its validity
Theory on capacity
MILLER 1956
- published an article THE MAGICAL NUMBER 7, +/- 2 where he reviewed existing research into stm
- said we can hold 7 items in stm, plus or minus 2
- believed stm stores chunks of info rather the individual numbers/letters
