Long term memory

• Bahrick 1975 (Duration)

  • Aim- To establish existence of long term memory and see whether there was any difference between recognition and recall
  • Procedure- 892 participants aged 17-74 from a USA high school. Recognition group shown sets of photos and a list of names and asked to match photo to the name and recall group were asked to name the people in the photos without being given a list of possible names

  
• Bahrick 1975 (Duration)

  • Results- Name matching: those who left high school up to 15 years earlier recalled 90% correctly when having to recognise people through photos, 80% after 25 years, 75% after 34 years and 60% after 47 years. Free recall was about 60% accurate after 7 years, dropping to less than 20% after 48 years
  • Conclusion- Memory is long lasting but often needs cues so even when free recall is a struggle cues allow memory to be retrieved

  
• Bahrick 1975 evaluation (Duration)

  • Strength- High ecological validity
  • Weaknesses- Extraneous variable (people may be friends with the people), time consuming research, school size makes it difficult and low temporal validity (now people can be found on social media)

  
• Baddeley 1966 (Encoding)

  • Procedure- Participants divided into 4 groups and shown a 10 word list drawn from 1 of 4 groups: acoustically similar, acoustically dissimilar, semantically similar and semantically dissimilar. Waited 20 minutes when participants were given another task to do, asked them to recall the words (delayed recall)
  • Results- Recall for semantically similar words- 55% accuracy VS semantically dissimilar, 85% accuracy
  • Conclusion- LTM encoded semantically as we get muddled when trying to recall things with similar meanings

  
• Baddeley 1966 evaluation (Encoding)

  • Strength- Standardised procedure so tests cause and effect, testing reliability
  • Weaknesses- Low in mundane realism/ ecological validity and lacks validity as participants can guess answers

  
• Wagenaar 1986 (Capacity)

  • Procedure- Wrote a diary for 6 years, recorded distinctive events in a diary (who/what/where/when). The day after he finished recording phase of research, he started testing himself on events using cues (who/what/where/when)
  • Findings- Often unable to recall the events from his own cues and so he spoke to people involved in the event and found he was able to remember once prompted. Found that he had an excellent memory for past events
  • Conclusion- Capacity of LTM is unlimited

  
• Wagenaar 1986 evaluation (Capacity)

  • Strengths- rich, detailed exploration and quantitative data
  • Weaknesses- Researcher bias (testing themselves), 6 years isn't a long time (lacks validity) and case study so not representative