Baddeley (1966)

• Baddeley (1996) studied how coding occurs in STM and LTM.

  
• Aim: To explore the effects of acoustic and semantic coding in Short-Term Memory and Long-term Memory
• Procedure:

  • In the study, participants were asked immediately after presentations, to recall, in serial order, a list of five words taken from a pool of words in the following categories:
  • acoustically similar words (e.g. man, mad, map)
  • acoustically dissimilar words (e.g. pen, day, few)
  • Semantically similar words (e.g. great, big, large)
  • Semantically dissimilar words (e.g. hot, old, late)
  • In the LTM study, each lists of words was extended to ten, and recall was tested after an interval of twenty minutes.

  
• Findings:

  • Words with similar sounds were much harder to recall using STM than words with dissimilar sounds so there was sound confusion
  • When participants were recalling from LTM, recall was much worse for semantically similar words than for semantically dissimilar words - there was confusion of meaning.
• Conclusions

  • STM relies heavily on acoustic coding indicated by confusion of sound
  • LTM primarily makes use of semantic coding indicated by confusion of meaning.
• Evaluation of Baddeley:

  ☹ A limitation of Baddeley's study is that it didn't use meaningful material. The words used in the study had no personal meanings to the P(s). When processing more meaningful info Ps may use sematic coding even for STM. This means that the results of the study have limited application. It may lack ecological validity as we do not recall acoustically/semantically (dis)similar words on a day-to-day basis.
• Evaluation of Baddeley (1966)

  ☺ Baddeley's findings make 'cognitive sense'. E.g. if you had to remember a shopping list you'd probably repeat it out aloud (acoustic rehearsal) while walking to the shops, but if you recall a book you had just read you'd recall the plot not a word for word recount.
• Evaluation of Baddeley

  ☺ There was high control. This was a lab experiment (see research methods) therefore shows a cause and effect relationship. It can easily be replicated to check the reliability of the results, as Baddeley had a standardised 20 minute break for the LTM recall group and every participant was shown the same words making this easy to replicate.
• Evaluation of Baddeley

  ☹ Posner and Keele (1967) found that visual coding also occurs in STM which illustrates how codes other than acoustics are used in the STM.