Coding, capacity & duration

What is the definition of coding, capacity & duration?

• Coding: the format in which information is stored in the various memory stores

• Capacity: the amount of information that can be held in memory

• Duration: the length of time information can be held in memory

Who found that there is a difference between acoustically similar & semantically similar words after different time periods?

Baddeley

Are people more or less likely to remember acoustically similar words when recalling immediately?

Less likely

What type of coding does STM use based on Baddeley’s findings?

Acoustic

What type of coding does LTM use & why?

Semantic → we find it harder to recall semantically similar words when there has been a delay

Who investigated the capacity of STM?

Miller / Baddeley / Jacobs

What did Miller say is the capacity of STM?

7 ± 2 items

What method can be used to increase the capacity of STM?

Chunking

What is the capacity of LTM?

Unlimited

What method did Peterson & Peterson use to investigate the duration of STM & what did they find was the duration of STM?

Trigrams & 18-30 seconds

Describe and evaluate coding, capacity and duration (16 marks)

Write your AO1 paragraph

• Coding refers to the format in which information is stored in the various memory stores. Capacity refers to the amount of information that can be held in a memory store. Duration refers to the length of time information can be held in memory.

• Research by Baddeley using acoustically & semantically similar words found that recall was worse with acoustically similar words when asked to recall immediately. However, when there was a delay of 20 minutes, recall was worse with semantically similar words. This suggests that short-term memory (STM) codes acoustically & long-term memory (LTM) codes semantically. The sensory register codes dependent on the sense, but the main ones are echoic (auditory) & iconic (visual).

• Research by Jacobs, using digit span tasks, found that the capacity of STM is limited with a mean of 7.3 words. Miller found that the capacity of STM is 7 ± 2 items. However, chunking can be used to increase this capacity. The capacity of LTM is unlimited. The sensory register has a very high capacity.

• Peterson & Peterson used trigrams to test the duration of STM & found that it was 18-30 seconds. Bahrick’s research of high school yearbook photos revealed that the duration of LTM is unlimited. The duration of the sensory register is less than ½ a second.

Describe and evaluate coding, capacity and duration (16 marks)

Write your strength AO3 PEEL (Bahrick)

• Point: One strength of research into coding, capacity & duration is that some studies have high external validity.

• Evidence: For example, Bahrick investigated the duration of LTM using high school yearbook photos to test participants’ recognition of former classmates.

• Explain: This tested meaningful, real-life memories rather than artificial stimuli (e.g. word lists), meaning the findings reflect how memory works in everyday settings.

• Link: As such, this increases the study’s ecological validity & suggests conclusions about the duration of LTM can be generalised beyond the laboratory.

Describe and evaluate coding, capacity and duration (16 marks)

Write your limitation AO3 PEEL (extraneous variables)

• Point: One limitation of research into coding, capacity & duration is that studies conducted in real-life settings may lack control over extraneous variables.

• Evidence: For example, in Bahrick’s study, some participants may have looked through their yearbooks more frequently than others, rehearsing the information over time.

• Explain: This could have influenced recall accuracy, making it difficult to determine whether memory performance was due to long-term retention or repeated exposure.

• Link: Overall, the findings may not provide a purely valid measure of LTM duration, reducing the internal validity.

Describe and evaluate coding, capacity and duration (16 marks)

Write your limitation AO3 PEEL (low mundane realism)

• Point: One limitation of research into coding, capacity & duration is that many studies use meaningless tasks with low mundane realism.

• Evidence: For example, Peterson & Peterson used trigrams to investigate the duration of STM, meaning the stimulus material was artificial.

• Explain: Memorising meaningless letter combinations does not accurately reflect how memory works in everyday life (e.g. revising for exams or remembering information for work meetings & presentations).

• Link: Therefore, such studies lack ecological validity, as performance on artificial tasks may not generalise beyond the laboratory.