bAHRICK ET AL 1975
duration of ltm
Aims: They wanted to investigate the duration of very-long-term memory (VLTM). They wanted to demonstrate that memories could endure in order to support the assumption that the duration of the LTM is infinate. They aimed to test the duration by testing recall of real-life information.
Procedures: Participants
included 392 American ex-high school student aged 17-74.
Recall was tested in four ways:
1. Free recall of the names of as many of their former classmates
as possible,
2. A photo recognition test where they were asked to identify former classmates
in a set of 50 photos, only some of which were their classmates,
3. A name recognition test,
4. A name and photo matching test.
This tested VLTM as time since departing high school varied, for some it was as long as 48 years. It was assessed by comparing their responses with high school year books, which contain all of the names and photos of the students in that year.
Findings: The
percentage recall was:
90% accuracy in FACE AND NAME RECOGNITION after 34 YEARS,
80% accuracy for NAME RECOGNITION after 48 YEARS,
40% accuracy for FACE RECOGNITION after 48 YEARS,
60% accuracy for FREE RECALL after 15 YEARS,
30% accuracy for FREE RECALL after 30 YEARS.
Conclusion:Findings show that classmates are rarely forgotten once recognition cues have been given. This supports the claim that people have very long term memories. These findings also the claim that recognition was better than recall. It demonstrates that VLTM exists for particular types of information, but it cannot be comcluded that it exists for all types of information.
Evaluation: This
study is a FIELD EXPERIMENT. Therefore the results can
be generalised to the real world. This creates HIGH
ECOLOGICAL VALIDITY.
Classmates are a particular type of information, they may have emotional significance so there would have been a great OPPORTUNITY FOR REHEARSAL , increasing the rate of recall. Therefore, the results CANNOT BE GENERALISED to other types of information.
Other Points: This
study supports the point of cue dependant retrieval, as upon the presentation
of a photo, the rate of recall increased.
Other points have also been found to affect the rate of recall, such as who the information was learnt from, if it has any personal signifiance and state dependant retrieval.
