Coding, duration and capacity of memory evaluation

Question 1

Eval for Coding - Artificial stimuli

Answer 1

Limitation of Baddeley’s study was that is used artificial stimuli rather than meaningful material. The word lists had no personal meaning to the participants. This means that the results may not be generalised to the wider population. Some people may use semantic code even for STM tasks. (Wickens et al)Suggests that findings from this study have limited application.

Question 2

Coding - LTM may not be exclusively semantic

limitation

Answer 2

LTM may appear to be semantic but not always. Frost showed that LTM recall was related to visual as well as semantic categories. Nelson and Rothbart found evidence of acoustic coding in the LTM. Therefore coding in the LTM is not simply semantic but can vary according to circumstances.

Question 3

Capacity- Size of chunks matter

strength

Answer 3

Size of the chunk affects how many chunks you can remember. Simon found that people had a shorter memory span for larger chunks than smaller chunks such as one syllable words. Continues to support that STM has limited capacity.

Question 4

Capacity-Not so many chunks (limitation)

Answer 4

Overestimation of the capacity of STM. Cowan concluded that the capacity of STM was only about 4 chunks. Suggests that seven items is an overestimation. Problem for the capacity of STM as miller claimed it to be 7 chunks but actually it is lower than that.

Question 5

Capacity- Individual differences

limitation

Answer 5

Capacity of STM is not the same for everyone. Jacobs found that the digit span increased with age. 8 year olds have 6.6 digit span while 19 year olds have 8.6. This can be due to the changes in brain capacity or the development of strategies such as chunking. Suggests that STM is not fixed for everyone but individual differences such as age matters.

Question 6

Capacity- Lacks validity

Answer 6

Jacobs research was conducted a long time ago. As a result it lacked adequate control. Some participants may have not performed well because they might have been disturbed. This means that results are invalid cause there were confounding variables which no controlled. However on the other hand results of this study have been confirmed on other research or it may not in fact lack validity

Question 7

Duration- Meaningless stimuli in STM study

Answer 7

Limitation of Peterson and Peterson (P&P) study is that stimulus was artificial. Memorising constant syllables has no real life relevance. So it lacks external validity. However we do try to remember irrelevant things like phone numbers so you can say that its not totally irrelevant.

Question 8

Duration- high external validity (strength)

Answer 8

Real life meaningful memories were studied. This supports LTM duration as when meaningless pictures were told to be recalled, recall rates were lower(Shepard et al). Downside of the research is that extraneous variables are not controlled such as ppt may have looked at their yearbook photos and rehearsed their memory over years. Could also be some demand characteristics as ppt may have guessed the aims of research so they rehearsed their memory over the years.

Question 9

Duration-STM results may be due to displacement

Answer 9

Critcism of the P&P study is that it did not actually measure what it set out to measure. Peterson’s study ppt were counting the numbers in their STM adn thsi