Coding, capacity and duration of memory

Question 1

What is ‘coding’?

Answer 1

Coding refers to the format in which information is stored in the various memory stores.

Question 2

Which psychologist investigated coding?

Answer 2

Alan Baddeley

Question 3

How did Baddeley investigate coding?

Answer 3

Baddeley gave different lists of words to four groups of participants to remember:

Group 1: Acoustically similar (e.g. cat, cab, can)
Group 2: Acoustically dissimilar (e.g. pit, few, cow)
Group 3: Semantically similar (e.g. great, large, big)
Group 4: Semantically dissimilar (e.g. good, huge, hot)

Participants were shown the original words an asked to recall them in the correct order.

Question 4

What did Baddeley find about one’s ability to code short-term memories?

Answer 4

When the participants had to complete the recall task immediately after hearing it, they tended to do worse with acoustically similar words.

Question 5

What did Baddeley find about one’s ability to code long-term memories?

Answer 5

If participants were asked to recall the word list after a time interval of 20 minutes, they did worse with semantically similar words.

Question 6

What did Baddeley conclude about the coding of long-term and short-term memories?

Answer 6

Baddeley conducted that information is coded semantically in LTM, and acoustically in STM.

Question 7

What is ‘capacity’?

Answer 7

Capacity refers to the amount of information that can be held in a memory store.

Question 8

Which psychologist conducted research into the digital span?

Answer 8

Joseph Jacobs (1887) developed a technique to measure digital span.

Question 9

How did Jacobs measure digital span?

Answer 9

Jacobs developed a technique where the researcher gives, for example, four digits and then the participant is asked to recall these in the correct order out loud. If this is correct the researcher reads out five digits and so on until the participant cannot recall the order correctly.

Question 10

What did Jacobs find to be the mean span for digits?

Answer 10

Jacobs found that the mean span for digits across all participants was 9.3 items.

Question 11

What did Jacobs find to be the mean span for letters?

Answer 11

Jacobs found that the mean span for letters across all participants was 7.3 items.

Question 12

Which psychologist investigated the span of memory and ‘chunking’?

Answer 12

George Miller (1956)

Question 13

How did Miller investigate the span of one’s memory?

Answer 13

Miller made observations of everyday practice. For example, he noted that things come in sevens: there are seven notes on the musical scale, seven days of the week and seven deadly sins. This suggests that the span (or capacity) of STM is about 7 items (plus or minus two). This can be written as 7±2.

Question 14

Miller investigated ‘chunking’. What is meant by this term?

Answer 14

Miller noted that people can recall five words as well as they can recall five letters. They do this by chunking, which refers to grouping sets of digits or letters into units or chunks.

Question 15

What is ‘duration’?

Answer 15

Duration refer to the length of time information can be held in memory.

Question 16

Which two psychologists conducted research into the duration of STM?

Answer 16

Peterson and Peterson (1959)

Question 17

How did Peterson and Peterson investigate the duration of STM?

Answer 17

Peterson and Peterson tested 24 undergraduate students. Each student took part in eight trials. On each trial the student was given a consonant syllable (also known as a trigram, such as YCG) to remember and was also given a three-digit number. The student was then asked to count backwards from that three-digit number until told to stop. This counting backwards was to prevent any mental reversal of the consonant syllable. On each trial, the students were asked to stop counting after a different amount of time: 3, 6, 9, 12, 15 or 18 seconds. This is called the retention interval.

Question 18

What percentage of Peterson and Peterson’s participants were able to recall the consonant syllable after counting for three seconds?

Answer 18

75% of participants were able to successfully recall the consonant syllable after counting for three seconds.

Question 19

What percentage of Peterson and Peterson’s participants were able to recall the consonant syllable after counting for 18 seconds?

Answer 19

10% of participants were able to successfully recall the consonant syllable after counting for 18 seconds.

Question 20

What did Peterson and Peterson conclude regarding the duration of STM?

Answer 20

They concluded that STM may have a very short duration, unless we repeat something over and over again (e.g. verbal reversal).

Question 21

Which psychologist conducted research into the duration of LTM?

Answer 21

Harry Bahrick (1975)

Question 22

How did Bahrick and his colleagues investigate the duration of LTM?

Answer 22

They studied 392 participants from the American state if Ohio who were aged between 17 and 74. High school yearbooks were obtained from the participants or directly from the schools. Recall was tested in various ways, including:

1. A photo-recognition test consisting of 50 photos, some
   from the participant’s high school yearbook
2. A free recall test where participants recalled all the
   names of their graduating class.

Question 23

How accurate were those tested within 15 years of graduation on the photo recognition test?

Answer 23

Participants who were tested within 15 years of graduation were about 90% accurate in photo recognition.

Question 24

How accurate were those tested 48 years after graduation on the photo recognition test?

Answer 24

After 48 years, recall declined to about 70% for photo recognition.

Question 25

Was free recall more or less accurate than photo recognition?

Answer 25

Free recall was less accurate than photo recognition

Question 26

How accurate were those tested 15 years after graduation on the free-recall test?

Answer 26

After 15 years, accuracy on the free-recall test was about 60%.

Question 27

How accurate were those who were tested 48 years after graduation on the free-recall test?

Answer 27

After 48 years, accuracy fell from 60% to 30%

Question 28

What did Bahrick conclude about the duration of LTM?

Answer 28

Bahrick concluded that LTM can last for a very long time.

Question 29

Evaluation point: ‘One limitation of Baddeley’s research into coding derives from his use of a manipulated environment’. Write a paragraph outlining this AO3 point.

Answer 29

One limitation of Baddeley’s research into coding derives from his use of a manipulated environment. For example, rather than using meaningful material, Baddeley opted to use artificial stimuli by providing his participants with a list of words, all of which had no personal meaning to the individuals. This therefore acts as a weakness because Baddeley’s findings fail to inform psychologists about how information is coded during every-day memory tasks.

• Lacks external validity
• Lacks mundane realism
• Participants may have acted on demand characteristics
• Has high internal validity
• Removes the influence of extraneous variables

Question 30

Evaluation point: ‘One limitation of Jacobs’ research into capacity evolves from his lack of control over the conditions’. Write a paragraph outlining this AO3 point.

Answer 30

One limitation of Jacobs’ research into capacity evolves from his lack of control over the conditions. Jacobs conducted his research in 1887, a time where psychology lacked adequate control over variables. This could lead one to assume that Jacobs’ participants may have been distracted when remembering their letters or numbers, which would in turn cause one to question the usefulness of his findings. This therefore acts as a limitation of Jacobs’ research because the evidence suggest that his findings cannot be used to draw conclusions about the capacity of one’s memory.

• Decreases the validity of his findings
• Influence of extraneous variables
• Decreases the internal validity
• Lacks scientific credibility

Question 31

Evaluation point: ‘One limitation of Miller’s research into capacity derives from conflicting research evidence’. Write a paragraph outlining this AO3 point.

Answer 31

One limitation of Miller’s research into capacity derives from conflicting research evidence. For example, in 2001 Cowen reviewed other research and concluded that the capacity for STM was only four chunks, not five. This therefore acts as a weakness of Miller’s study because the evidence fails to support his theory that information can be recalled by grouping sets or units or letters into five sets.

• Lacks reliability
• Lacks temporal validity

Question 32

Evaluation point: ‘One limitation of Peterson and Peterson’s research into the duration of STM derives from their use a laboratory environment’. Write a paragraph outlining this AO3 point.

Answer 32

One limitation of Peterson and Peterson’s research into the duration of STM derives from their use a laboratory environment. For example, Peterson and Peterson asked their participants to memorise a consonant syllable, which is an example of artificial stimuli. This acts as a weakness because their study fails to reflect real-life memory tasks.

• Lacks external validity
• Lacks real-life application
• Demand characteristics which lowers the validity
• Lacks mundane realism

Question 33

Evaluation point: ‘One limitation of Peterson and Peterson’s research into the duration of STM derives from conflicting research evidence’. Write a paragraph outlining this AO3 point.

Answer 33

One limitation of Peterson and Peterson’s research into the duration of STM derives from conflicting research evidence. For example, in their study the participants were asked to count down during the retention interval. Modern memory theories suggest that information in the STM is displaced, suggesting that Peterson and Peterson’s theory is not compatible with contemporary psychology. This therefore acts as a weakness because it suggests that their research findings regarding the duration of STM are no longer relevant when studying the memory today.

• Lacks temporal validity
• Lacks reliability

Question 34

Evaluation point: ‘One limitation of Bahrick’s research into the duration of LTM comes from differing research findings’. Write a paragraph outlining this AO3 point.

Answer 34

One limitation of Bahrick’s research into the duration of LTM comes from differing research findings. For example, in 1967 Shepherd used artificial stimuli to test the duration of LTM and found that recall rates were lower than those found in Bahrick’s study. This therefore acts as a limitation of Bahrick’s research because alternative evidence has failed to support his findings, which in turn causes one to question whether his study should be relied upon to draw conclusions from.

• Lacks external validity
• Lacks temporal validity
• Lacks reliability
• Bahrick’s study is more likely to be valid because he used a longitudinal study