Evaluation of Research on Coding, Capacity and Duration

• research on coding strength 


  consistent evidence- Baddeley
• consistent evidence 


  Baddeley’s findings that STM is coded acoustically and LTM semantically has stood the test of time= an important step in out understanding of the memory system which led to the multi-store model
• research on coding weakness 


  use of artificial materials
• use of artificial materials 


  issue with the stimuli used in the experiment not being meaningful material

  e.g. word lists have no personal meaning to participants- findings may not tell us as much about coding in different kinds of memory tasks, especially in everyday life. when processing more meaningful information people may use semantic coding even for STM tasks= limited application
• research on capacity strength 


  research has ben replicated
• research has been replicated 


  Jacobs’ study is a very old one and early research in psychology often lacked adequate controls

  e.g. some participants‘ digit spans might have been underestimated because they were distracted during testing. however, Jacobs’ findings have been confirmed by other, better controlled studies since the 1800s.

  suggests Jacobs’ study is a valid test of digit span in STM
• research on capacity weakness 


  capacity overestimated- Cowan
• capacity overestimated 


  Cowan (2001)- reviewed other research and concluded that capacity of STM is only about 4 (plus or minus 1) chunks
• research on duration weakness


  artificial stimuli
• artificial stimuli 


  Peterson and Peterson= artificial materials. recalling consonant syllables doesn‘t reflect most everyday memory activities where what we are trying to remember is meaningful- lacks external validity
• artificial stimuli COUNTER

  Bahrick et al. study= high external validity. researchers investigated meaningful memories (of people’s names and faces). when studies on LTM were conducted were conducted with meaningful pictures to be remembered, recall rates were lower. Bahrick et al.’s findings reflect a more ‘real’ estimate of the duration of LTM