,Coding capacity ,
+ duration of memory
spec features of each
coding capacity and duration
:
store :
,
the various Research
coding coding
: on :
formats in which Once information is in the
memory system ,
it is stored in various formats,
memory
is stored
depending on the memory store. The process of converting one form of info to -
capacity the amount another is called coding Alan Baddeley (1966) gave different lists of words
: .
of information that to a participant to remember :
can be held in a ① acoustically similar
memory store ② acoustically dissimilar
duration : the
length ⑤ Semantically Similar
of time that info ④ semantically dissimilar
can be held in the Participants were shown the
original words and asked to recall them in the
correct order. When had to recall the
immediately tended
memory they words after ,
they
Short-term memory : to do Worse with the acoustically similar words due to the short term
memory
the limited
capacity being acoustically stored.
Store:
memory Coding After 20 minutes the participants did Worse on ,
the
semantically similar words,
is
mainly acoustic,
suggesting that the LTM is semantically stored .
capacity is between Research capacity digit span :
on :
5-9 items and Joseph Jacobs (1887) developed a technique to
duration is between measure digit Span. The researcher gave 4
digits +
18-30 seconds the participant was asked to recall these in the correct
long-term memory
:
order. If this is correct then the researcher will recall 5
,
the permanent digits + so on until the participant cannot recall the
:
order This determines someone's digit
memory store
coding correctly
.
is Span-the 7 3
.
mainly semantic, mean
being around .
has unlimited capacitySpan of chunking
Memory
+ :
George Miller (1956) observations that most 75 .This
and unlimited made
things come in
duration- that STM items. However , he also
suggests the
capacity of the is about 7
noticed that people recall 5 letters as well as
they do 5 numbers.They do
this
through chunking letters numbers into units .
Research on duration duration of STM : :
Duration is the
defining feature of the STM Peterson .
and Peterson (1959)
tested 24 Each Student eight trials. On
undergraduate students s. took part in
each trial , the student was
given a consonant
syllable in the form of a
trigram 3-digit number to count backwards on to prevent rehearsal.
and a
On each trial
they were told to stop after a different amount of time called
, ,
the retention interval. The findings suggest that STM
may have a very short
duration unless there is verbal rehearsal .
Duration of LTM :
Banrich et al (1975) studied 392 participants from Ohio who were between 17 -
74 Photo
.
recognition and free recall were tested . Panicipants who were with in
15
years of graduating were about 90% accurate in photo recognition
and 60% in free recall After 48 years they were 70% accurate for photo
.
,
recognition + 30% for free recall .
coding capacity duration
: : :
X artificial Stim Wi X
confounding research (Cowan , 2001 , X
meaningless Stimuli in STM
X personal differences in found 34 chunks) ~ higher external + ecological
memory X lacked
validity Validity in P+ P (1975)