Memory studies

What studies looks at memory capacity and by who

Diget span technique (Jacob) and the Span of memory and chunking (Miller)

What studies looks at memory encoding and by who

Memory ecoding (Baddely)

What studies looks at memory duration and by who

Duration of STM (Peterson + peterson) and Duration of LTM (Bahrick et al)

Digit span technique (Jacobs): method, findings and evaulation

Method:

• sequence of numbers from 0 to 9

• P must immediatally recall these numbers

• Start at 4 and then sequence gets longer when the answers are correct

Findings:

Mean span was 7.3

Evaluation:

Pro: Is avlid as it has been replicated

Con: Lacks termperol validty and some Ps may have been distracted

Span of memory and chunking (Miller): method, findings and evaulation

Method:

• Made observations of everyday life

• eg 7 days in a week, 7 deadly sins ect

Findings:

Span of LTM is 7+-2 items

Evaluation:

pro: Introduces chunking

Con: May have overstamated STM ability

Memory encoding (Baddely): method, findings and evaulation

Method:

• Group of students recalled words in four groups: acousictally similar and not, semantically similar and not

• Asked to recall immediatley

• Or asked to recall after 20mins

Findings:

Information is coded acoustically is STM and sematically in LTM

Evaluations:

Pros; Clear difference between two memory stores and general idea has temperal validity

Con: Artificial stimuli

Duration of STM (Peterson +Peterson): method, findings and evaulation

Method:

• 24 students in 8 trails each

• P was given a consant syllable

• Had to count down from a 3 diget number (no mental rehersal)

• Had to recall it after: 3, 6, 9, 12, 15, 18 seconds

Findings:

After 3 seconds recall was 80% and after 18 seconds recall was 3%

Evaluation:

Pro: High internal validity

Con: Results may be due to the interference from countring backwards rather than decay

Duration of LTM (Bahrick et al): method, findings and evaulation

Method:

• Studied 392 Americans between 17 and 74 years old

• Recall was tested using yearbooks

• Free recall: recalling names

• Photo recognition

Findings:

• Within 15 years of graduation 90% were accurate in photo recgonition and 60% in free recall

• Within 48 years of graduation 70% were accurate in photo recgonition and 30% in free recall

Evaluation:

Pros: High external validity

Cons: High extraneous variables