Peterson and Peterson (1959) Short-term Retention of Individual Verbal Items

Question 1

Aim

Answer 1

– To test the true duration of short-term memory

Question 2

Procedure

Answer 2

– 24 students were repeated out loud a trigram they heard. Then, say out loud a three-digit number and count backwards in threes/fours.– When signalled by a red light, they had to recall the trigram. This was done 8 times, with time delays of 3n until 18 times.

– The procedure was repeated 48 times with diff trigrams

Second experiment:
– Same procedure, but some time was given to repeat the trigram (silently/vocally) before counting backwards

Question 3

Results

Answer 3

The longer each student had to count backwards, the less likely they were to recall the trigram.
Count backwards after 3 seconds: 80% recall
18 seconds: less than 10% recall

Second experiment:
The extra time increased frequency of recall; had more time to consolidate the information.
A similar decline was shown.

Question 4

Conclusion

Answer 4

With the participants unable to rehearse the trigrams, information in our STM fades rapidly; only 10% could be recalled after 18 seconds.

Question 5

Strengths

Answer 5

– Good control and standardised procedures
Used fixed timings, controlled extraneous variables
– Practical application
Demonstrates how interference (verbal distractions) can affect our ability to retain information
We should avoid distractions when trying to focus

Question 6

Weakness

Answer 6

– Lacked mundane realism

We do not need to remember trigrams in our everyday life; unrealistic test of memory