Coding, capacity and duration of memory

Coding

Baddeley (1966) pps memorised lists of words: acoustically similar, semantically similar, acoustically different, semantically different.

Found STM coded acoustically and LTM coded semantically

Capacity:

Jacobs (1887) item span measured, 9.3 for digits, 7.3 for letters

Miller (1956) found it was 7 units +2 or -2

Duration:

Peterson and Peterson (1959) letter and 3 digit number, found STM has a duration of 18-30s

Bahrick (1975) graduate photos experiment, found after 15 years pps recall was 90% accurate showing LMT duration is unlimited

Artificial tasks

Memorising letters and numbers is not reflective of memorising in everyday life, showing it lacks ecological validity

Confounding variables

Pps could have done mental rehearsal, the numbers/letters could have held significance in everyday life making them easier to remember, Bahrick’s pps could have looked at their yearbook more/not have known many people in their year

Replicable

Simple variables lead to easy replication, high test-retest reliability