Peterson & Peterson (1959) Flashcards
What was the aim of the study?
To test the duration of STM
How many students were tested in Experiment 1?
24
What is a trigram?
Three letters together that don’t make a word e.g. TXZ
How many experiments were involved in this study?
2
Where were the participants from?
A Psychology course at Indiana University.
What was the purpose of the black box? (Experiment 1)
When a green light appeared, that meant the trial had began.
A red light meant that the participant had to stop counting backwards and recall the trigram.
How many practise trials did each participant do? (Experiment 1)
2
What was the procedure of the trial? (Experiment 1)
At the beginning of the trial, the experimenter would spell out a trigram followed by a number that they had to count backwards from.
What were the numbers that the participants had to count backwards in? (Experiment 1)
3’s or 4’s
What was the purpose of counting backwards in 3’s or 4’s? (Experiment 1)
It was an interference task to stop them rehearsing the trigram.
What was the interval time between each trial? (Experiment 1)
15 seconds
How many trials did each participant do in total? (Experiment 1)
8 times at each of the recall intervals
What were the 6 recall intervals? (Experiment 1)
3, 6, 9, 12, 15 and 18 seconds
What were the results for the 3 second interval? (Experiment 1)
Participants could recall 50% of the trigrams correctly.
What were the results of the 15 second and on interval? (Experiment 1)
The correct answers dropped to only 10%
What is a conclusion of the study? (Experiment 1)
Short term memory has a limited duration because the longer the participant was counting backwards for, the more trigrams they remembered incorrectly.
How many participants were in experiment 2?
48
What were the two conditions of experiment 2?
Condition 1 was where the participants were given a trigram and they had to repeat it out loud. They were then stopped and asked to count backwards in 3’s. (Vocal group)
Condition 2 was where the participants were given a trigram but they were asked not to rehearse it out loud (silent group). After a certain amount of time, they had to count backwards from a number.
What were the interval periods for experiment 2?
Immediate recall of 1 to 3 seconds and also 3, 9 and 18 seconds.
What were the results of experiment 2?
Participants in the vocal group were better at recalling the trigram correctly and the longer they rehearsed the trigram outloud, the better they were.
