Coding, Capacity and Duration

• Coding


  The format in which information is stored. Stored through the five senses
• Who Did Research On Coding?

  Baddely
• Process of Baddely's Experiment on coding

  Group 1 - Accoustically similar

  Group 2 - Acoustically disimilar

  Group 3 - Semantically similar

  Group 4 - Semantically disimilar

  They were given a list of original words in wrong order. Had to recall in correct order. (LTM 20 Min Interval)
• Result of Baddley's Experiment For coding STM

  Confusion between acoustically similar words
• Result of Baddley's Experiment for coding in LTM

  Confusion between semantially similar words
• Conclusions for Baddley's Experiment on coding

  STM - Acoustic confusion, coded acoustically

  LTM - Semantic confusion, coded semantically
• Positive Evaluation for Baddley's Experiment on coding

  Cause and effect is shown.

  Replicable
• Negative Evaluation of Baddley's Experiment on coding

  Artificial Stimuli - Cautious about generalising

  Lacks external validity
• What is Capacity?

  Amount of information that can be held.
• Research for Capacity

  Jacobs and Miller
• Method for Jacob's Study on capacity

  Aim - See how much info STM can hold at one time

  Developed a technique - Digit Span

  Research gave a certain number of digits then the PP recalled in correct order. If recalled correctly, amount of digits increased. Determines individuals digit span.
• Results of Jacob's Study on capacity

  7.3 letters

  9.3 words
• Positive Evaluation(s) of Jacob's Study on capacity

  Supported by other research - More validity
• Negative Evaluation(s) of Jacob's Study on capacity

  Conducted a long time ago - low temporal validity

  Lacked adequate control

  Lacks ecological validity

  Lacks Mundane realism

  May not have controlled for confounding variables - reduces validity
• What Did Miller's Study Discover?

  Instead as keeping the information as individuals, the unit of informaiton can be increased by chunking.
• What is Miller's Magic Number?

  7 +/- 2 (5-9 chunks)
• Evaluation Points For Miller's Study

  Lacks EV

  Miller may have overestimated STM capacity

  Cowan reviwed the research and found it was only 4 chunks.
• AO3 of Capacity

  Other factors at play - Age and practice effects

  Nowadays limitations of STM seen as due to processing limitations associated with STM
• What is Duration?

  Length of time information can be held
• Who Conducted STM Duration Research?

  Peterson and Peterson
• Method for Peterson and Peterson's Study on duration

  Each student was given a nonsense triagrams (3 consenants), as well as a 3 digit number. The student had to count backwards from this number (prevents mental rehearsal) told to stop counting at different intervals.
• Results for Peterson and Peterson's Study on duration

  Amount recalled correctly:

  3 seconds - 90%

  18 seconds - 5%

  (Significant difference between them)
• Conclusion for Peterson and Peterson's Study on duration

  STM has a very short duration unless it is rehearsed, I.e. Mental Rehearsal.
• Positive Evaluation of Peterson and Peterson's Study on duration

  Operationalised - Replicable

  Controlled for confounding variables (counting backwards)

  People do try and remember phone numbers - relevance
• Negative Evaluation of Peterson and Peterson's Study on duration

  Artificial situation - Lacks ecological validity

  Methodology flawed - Different triagrams used in each trial (interference)

  Memory trace disappears if not rehearsed - Alternate explanation = information is displaced.
• AO3 of Duration in STM

  Brief duration is due to displacement as it has limited capacity.

  Little way in research considering the duration in other forms of stimuli I.e Visual Images.
• How is STM Coded?

  Mainly Acoustic
• Capacity of STM?

  7 +/- 2 (5-9)
• Duration of STM?

  Max 30 seconds
• How is the LTM Coded

  Mainly Semantically
• Capacity of LTM?

  Huge
• Duration of LTM

  Very long time - Lifetime?