A03 Coding, Capacity And Duration Of Memory

• Artificial stimuli- Baddeley


  Baddeley's study used artificial stimuli rather than meaningful material. Words lists had no personal meaning to the ppts and thus, we should be cautious to generalise findings to different memory tasks.
• Contradiction to Baddeley's study

  When processing more meaningful tasks, people may still use semantic coding even for STM tasks which is limited application
• Lacking validity- Jacobs


  Jacobs' study was a long time ago and psychology research then lacked adequate control. E.g. Some ppts may have been distracted so they did not perform as well and thus, the results are not valid due to CVs that are not controlled
• Jacob study strength


  Other studies and research support the results of Jacobs' study- so supporting validity
• Not so many chunks- Miller

  Miller may have over-estimated capacity of STM. E.g. Cowan reviewed other research and concluded capacity of STM was only 4 chunks which suggests Miller's lower estimate of 5 was more appropriate than 7
• Meaningless stimuli in STM study

  Stimulus was artificial: trying to memorise consonant syllables does not represent real life activities trying to remember meaningful things and thus, lacks external validity . However, sometimes we memorise useless things like phone numbers so experiment is not entirely useless.
• Higher external validity- Bahrick's study

  Bahrick's study had high external validity as meaningful studies measured. E.g. Shepard who used meaningless pictures had a reduced LTM recall rate. Lack of control of confounding variables as ppts could look at the yearbook and rehearse memory over the years
• Criticising Peterson and Peterson

  Memory trace disappears if not rehearsed (spontaneous decay) . Or, STM has a limited capacity so new information pushes current information out. In the experiment, counting down may have kicked out memory of consonant syllables