Peterson and Peterson
Aim
To investigate the duration of short-term memory.
Lloyd and Margaret Peterson aimed to test the hypothesis that information which is not rehearsed is lost quickly from short-term memory.
Procedure
A laboratory experiment was set up in which 24 participants, all of whom were students, were asked to recall trigrams. A trigram is a meaningless set of three syllables, such as JBY, OIT or TYN.
Participants were prevented from rehearsing the trigrams by being given a delaying task where they had to count backwards in threes or fours until they saw a red light appear, at which point they would be asked to recall the trigrams. The delay between reading the trigrams and recalling them was after 3, 6, 9, 12, 15 or 18 seconds.
Result
It was found that after a three-second delay participants were able to successfully remember up to 90% of the trigrams. However, after 18 seconds recall fell to just 2%.
Conclusion
Peterson and Peterson concluded that information vanishes rapidly from short-term memory if participants are not able to rehearse information. The study is supportive of the multi-store model and how rehearsal takes place.
Evaluation
Strengths
- The research study provides good evidence for the Multi-store Model of Memory
- All procedures were standardised, which means that the study is both scientific and replicable to check that results are reliable
Weaknesses
- The study lacks ecological validity as people are not asked to recall trigrams as part of everyday use of memory
- The sample size of 24 is very low and therefore this is not representative of the population at large
- All participants were college students who, again, are not representative of the general population