classic: baddeley

when did Baddeley carry out his study?

1966

what is meant by acoustic?

sound

what is meant by semantic?

meaning

what did Baddeley want to test?

whether short term memory and long term memory were different or whether they existed on a continuum

what did Baddeley know about short term memory from his previous research?

STM for word sequences is worse for acoustically similar words than semantically similar words, so STM encodes acoustically

what was the aim of Baddeley's study?

to find out if LTM encodes acoustically or semantically

what type of experiment was used in Baddeley's study?

lab experiment

what was the experiment designed to test?

order recall of acoustically and semantically similar word lists

who were the participants used in Baddeley's study?

a mix of male and female volunteers from the applied psychology research unit subject panel, Cambridge

how many participants were in each group?

20

what was the groups design used in Baddeley's study?

independent groups design as participants were assigned to 1 of 4 conditions

what was the independent variable?

acoustic or semantic similarity

what was the dependent variable?

score on the recall test of 10 words, words must be recalled in the correct order

how many word lists were used?

4 lists of 10 words, 1 for each condition

what was the word list given to group A?

10 acoustically similar words

what was the word list given to group B?

10 acoustically dissimilar words

what was the word list given to group C?

10 semantically similar words

what was the word list given to group D?

10 semantically dissimilar words

what did lists B and D act as?

control groups to lists A and C to allow comparable data

how did Baddeley ensure word length would not be a variable affecting data?

he made sure all words were one syllable

what was each list of 10 words presented by?

a slide projector

how were the words presented to participants?

in the correct order one at a time for 3 seconds

what was the interference task participants were given after the presentation of the words?

6 8-digit number sequences were read out at 1 per second and participants had 8 seconds to recall the numbers

what did the interference task prevent participants from doing?

rehearsing the word list to keep it in their short term memory

what did participants have to do after the interference task?

they had 1 minute to recall the 10 words in the order they had been presented in

how many times were participants presented with the same word list?

4

what was the 15 minute interference task participants were given after the 4 learning trials?

copying 8-digit number sequences at their own pace

what were participants given after the 15 minute interference task?

a surprise retest on the word list order

why was the word list in a random order made visible on a card in the room during learning, testing and the retest?

the study was a test of the order words were presented in rather than actually learning them

how did the appearance of the word list in a random order on a card in the room help to eliminate individual differences?

some words may be more familiar to some participants which could affect recall

what were the results of the acoustically similar and dissimilar word lists?

acoustic encoding did not affect LTM recall as the number of words recalled in the order correctly was 70-80% for both groups

what were the results of the semantically similar and dissimilar word lists?

LTM encodes semantically as participants recalled significantly fewer similar words with 85% from list C and only 55% from list D

what was concluded by Baddeley's study?

LTM uses semantic encoding which makes it different from STM

what statistical test did Baddeley use to test whether his results were significant?

Mann-whitney U

why was Mann-whitney U the appropriate statistical test for Baddeley to use to test the significance of his results?

he was looking for a difference, used an independent groups design and collected interval level data (the number of words recalled in the correct order out of 10)

what is long term memory useful for?

sorting things into meaningful categories