Memory (Peterson and Peterson)

Procedure 1

Trigrams were presented and participants were instructed to count backward in threes and then were asked to recall the trigram

Number of participants

24

Procedure 2

Participants were allowed to rehearse the trigram before counting backwards

Results of Procedure 1

Prevention of rehearsal led to loss of more than 90 percent of the material

Results of Procedure 2

Repetition allowed for more information to be retained

Strengths of Peterson study

Standardized procedure, practical applications like the multi store model

Weaknesses of Peterson study

Lack of ecological validity, use of psychology students may reduce validity

What did Peterson study proved

Short term memory duration is 18-30 seconds