duration Flashcards
duration
the length of time information can be held in memory.
Margaret and Peterson research on duration of STM
tested 24 undergraduate students and each took part in 8 trials. On each trial a student was given a trigram and a 3 digit to count backwards from.This was done to avoid mental rehearsal of the trigram.They were told to stop counting and recall the trigram at different retention intervals
findings of Margret and Peterson
There finding show that the STM has a very short duration unless we do verbal rehearsal
evaluation of Peterson and Peterson’ research
one limitation is the stimulus material was artificial.memorising trigrams doesn’t reflect most real life memory activities .Therefore it lacks external validity.However we do try to remember meaningless things e.g phone numbers,therefore this study is not totally irrelevant.
Bahrick et al ‘s study on duration of LTM
studied 392 participants from ohio who were aged between 17 and 74.High school yearbooks were obtained from the participants or directly from some school.recall was tested using photo-recgonition test consisting of 50 photos and free recall test,where part’s recalled all the names of their graduating class.
Findings from bahrick’s study on the duration of LTM
part’s who were tested within 15 years of graduation were about 90% accurate in photo recognition.After 48 years recall declined to 70% for photo recognition After 15 years free recall was 60% accurate,dropping to 30% after 48 years.
conclusion to bahrick et al ‘s research on duration of LTM.
this show that LTM can last a very long time.
evaluation of Bahrick et al ‘s study on duration of the LTM
strength=high in external validity as real life meaningful memories were studied.when research on LTM used meaningless pictures recall rates were lower(Shepard)
However the downside of real life research is the confounding variables are not controlled e.g part’s may have looked at photobook recently.
