Memory: Coding, capacity, and duration Flashcards
What is encoding?
The format in which memory is stored.
What is capacity?
The amount of information that can be stored in memory.
What is duration?
The length of time information can be stored in memory.
What is the coding, capacity and duration of sensory memory?
Coding: Modality specific.
Capacity: Unknown, but very large.
Duration: Approximately 250ms.
What is the coding, capacity, and duration of short-term memory?
Coding: Acoustically.
Capacity: 7 +/-2 chunks of information.
Duration: Approximately 18-30 seconds unless information is rehearsed.
What is the coding, capacity, and duration of long-term memory?
Coding: Semantically.
Capacity: Potentially unlimited.
Duration: Lifetime.
Name a study which researches the capacity of short-term memory.
Jacobs (1887).
Miller (1956).
How did researchers measure short-term memory?
A digit span task was used.
What were the results of Jacobs’ (1887) study?
The average span for numbers was 9.3 items.
The average span for letters was 7.3 items.
What did Miller suggest about the capacity of short-term memory?
Miller concluded that people can hold 7 +/-2 chunks of information. He also suggested that the capacity of short-term memory can be increased if items are chunked together. This can occur when we can find links between the items.
Name the limitations of research into the capacity of short-term memory.
Miller may have overestimated the capacity of short-term memory.
Miller did not specify the size of the chunks.
Individual differences are not taken into account.
Lack of ecological validity.
How is Miller’s overestimation of the capacity of short-term memory a limitation?
Cowan (2001) reviewed multiple studies and concluded that short-term memory (STM) capacity was closer to 4 chunks, rather than Miller’s magic number of 7 +/-2. This finding implies that Miller’s estimate might be inflated, as his methodology may not have accounted for individual differences in cognitive processing, leading to variability in STM capacity. Consequently, this calls into question the validity of Miller’s magic number, reducing the generalisability of his conclusion.
Why is Miller’s lack of specification on the size of the chunks a limitation?
Simon (1974) found that STM capacity varies with chunk size; participants could remember fewer larger chunks, but more smaller chunks. This indicates that Miller’s concept of chunking lacks specificity, as it does not account for the variability in STM capacity based on chunk complexity. Simon’s findings therefore highlight the need for a more nuanced understanding of how chunk size affects STM capacity, which would therefore enhance the validity of memory research.
