classic study: baddeley (1966b)

• baddeley: aim

  to investigate the influence of acoustic and semantic word similarity on learning and recall in short-term and long-term memory
• baddeley: sample

  total of 72 men and women from the applied psychology research panel in cambridge took part in the research

  using an independent measures design
• baddeley: experiment three procedure (word lists)

  list A included 10 acoustically similar words (man, cab, can, cad, cap, mad, max, cat, map)

  list B included 10 acoustically dissimilar words (pit, few, cow, pen, sup, bar, day, hot, rig, bun)

  list C included 10 semantically similar words (great, large, big, huge, broad, long, tall, fat, wide, high)

  list D included 10 semantically dissimilar words (good, huge, hot, safe, thin, deep, strong, foul, old, late)
• baddeley: experiment three procedure

  the participants were assigned to one of the four word list groups

  the were four trials for the same list

  these words were presented on a slide projector, 1 word every 3 seconds with a 2 seconds slide change over

  the participants then completed a distraction task

  this was 6, 8 digit recalls which were presented 1 digit per second

  the participant then had to recall the words from the list in the order they learnt them (serial recall)

  this was followed by a 15 min self paced copying task before a final 'surprise' of the words in the correct order
• baddeley: results (acoustic similarity)

  there was a tendency for initial learning to be impaired by acoustically similar words compared to dissimilar words in STM

  however once the acoustic words were learnt there was no significant difference in the recall between trial 4 and the retest between acoustic similar and dissimilar words
• baddeley: results (semantically similarity)

  the semantically similar words showed slower learning over the 4 trials than the semantically dissimilar words

  semantically similar words had significantly lower level of recall in the surprise retest than the semantic dissimilar words in LTM
• baddeley: conclusion

  it appears that LTM is impaired by semantic similarity (the meaning of words)

  LTM uses semantic coding extensively although not exclusively (as there was no evidence of forgetting in the control group)

  it also identified that although the initial information may be encoded acoustically (STM) for it to be retained there needs to be semantic meaning linked to it
• baddeley: reliability (+)

  baddeleys procedure is standardised as all participants completed the same tasks such as every participant did four trials of the same word list with a surprise retest (e.g semantically similar words) which were presented on a slide projector

  this means the study by baddeley is high in reliability as it can be easily replicated in the future to see if the results on the influence of acoustic and semantically similar word learning and recall in the STM and LTM are consistent over time
• baddeley: validity (+)

  the study had high levels of controls such as the words were presented for 3 seconds with a 2 seconds changeover to isolate and eliminate the effects of extraneous variables from impacting on results

  this means the study is higher in validity as it is accurately measuring the cause of the influence of acoustic and semantically similar word learning and recall in the STM and LTM
• baddeley: independent measures design (+)

  the study uses independent measure design so there is a different group of participants taking part in only one condition each, semantically similar or dissimilar or acoustically similar or dissimilar

  this means that the participants are less likely to guess the aim of the research so they are less likely to show demand characteristics and try to please or displease the researcher so the outcome of the study is more likely to be an accurate reflection of memory processing in the STM and LTM
• baddeley: independent measure design (-)

  the participants only took part in one of the four conditions, acoustically or semantically similar or dissimilar

  this means that there is an increased chance if individual differences affecting the outcome of the study looking into processing in the STM and LTM so the results may not be an accurate reflection of all peoples memory due to potential unique memory capabilities not being controlled for