Capacity of the STM Flashcards
What is STM?
A temporary place for storing information.
What is the capacity of the STM?
Limited, unless maintained through rehearsal processes and put in LTM.
When did Jacobs’ conduct his STM research?
1887.
What was the aim of Jacobs’ 1887 research?
To investigate how much can be stored in the STM at one time.
Outline the general procedure of Jacobs’ 1887 study.
Used memory span as a measure of how much can be stored in STM at one time.
He presented participants with a random sequence of digits or letters and then asked them to repeat the items back in the same order - (serial order).
Memory span was operationalised as the ‘longest sequence of items recalled accurately at least 50% of the time’.
What were the two findings from Jacobs’ 1887 study?
The average number of items recalled was between 5 and 9.
Digits were recalled better than numbers.
What was concluded from Jacobs’ 1887 study?
STM has limited capacity.
Outline 2 evaluative points from Jacobs’ 1887 study?
Approach is artificial and lacks mundane realism, as the task was not representative of everyday memory demands.
External validity is questioned because of the setting (controlled) and the nature of the task.
The study has great historical importance as it represents the first systematic attempt to assess the capacity of memory.
Findings can be applied to improve memory e.g. telephone numbers and postcodes are based on this ideas of total digit span.
Digits may only have been recalled better than numbers as people are more familiar with memorising numbers than letters e.g. telephone numbers. This shows that Jacobs has not excluded confounding variables from the experiment.
Outline Miller’s study from 1956.
Reviewed research to find the capacity of STM to be between five and nine items. (‘The magical number).
He also found that the ‘chunk’ was the basic unit of STM.
This means five to nine chunks can be held at any one time, increasing the store’s capacity.
Miller supports Jacobs, suggesting 5-9 items is a valid capacity for STM.
Outline Simon’s 1974 study.
Supports Miller’s views on ‘chunking’.
This is because they tested Miller’s idea of ‘chunking’ with words - two word phrases, and eight word phrases: finding that STM capacity should be measured in terms of chunks.
However, they suggested that chunking varies with the type of material being recalled and the amount of information contained within the chunks.
This suggests that Miller’s ideas are valid, but challenges the universality of the concept.
What is chunking?
Pieces of information grouped together into meaningful sections).
What constitutes a chunk depends on personal experiences.
E.g. PE = physical education, LOL = laugh out loud.
Chunks vary from person to person.
