Features of stm and LTM

What did Baddeley (1966) investigate?

Whether STM and LTM use different types of coding.

What were participants worse at recalling immediately in Baddeley's study?

Acoustically similar words.

What does poor immediate recall of similar sounding words suggest?

STM codes information acoustically.

What were participants worse at recalling after 20 minutes?

Semantically similar words.

What does poor long term recall of semantically similar words suggest?

LTM codes information semantically.

What is a limitation of Baddeley's study?

Artificial word lists reduce external validity.

What is a strength of Baddeley's study?

It supports the distinction between STM and LTM coding.

What did Jacobs (1887) study?

The capacity of STM using digit and letter span tasks.

What was the average digit span in Jacobs' study?

9.3 items.

What was the average letter span in Jacobs' study?

7.3 items.

What did Miller propose about STM capacity?

The magic number 7 plus or minus 2.

What is chunking?

Grouping information to increase STM capacity.

What is a limitation of Miller's findings?

Cowan found STM capacity is closer to 4 plus or minus 1 chunks.

What is a strength of Jacobs' study?

Controlled procedure increases reliability.

What is a limitation of Jacobs' study?

Artificial stimuli reduce ecological validity.

What did Peterson and Peterson (1959) investigate?

The duration of short term memory.

What task did Peterson and Peterson use?

Participants learned trigrams while counting backwards to prevent rehearsal.

Why did participants count backwards in Peterson and Peterson's study?

To stop maintenance rehearsal of the trigram.

What was the recall after 3 seconds in Peterson and Peterson's study?

80 percent.

What was the recall after 18 seconds?

3 percent.

What did Peterson and Peterson conclude about STM duration?

STM lasts around 18 seconds without rehearsal.

What is a strength of Peterson and Peterson's study?

High internal validity from controlled lab procedures.

What is a limitation of Peterson and Peterson's study?

Use of meaningless trigrams reduces external validity.

What did Bahrick et al. (1974) investigate?

How long LTM can last using real life memories.

Who were the participants in Bahrick's study?

392 American adults aged 17 to 74.

What materials were used in Bahrick's study?

High school yearbooks.

What two recall methods were used in Bahrick's study?

Photo recognition and free recall.

How accurate was photo recognition after 15 years?

About 90 percent.

How accurate was photo recognition after 48 years?

Around 70 percent.

What does Bahrick's study show about LTM duration?

LTM can last a lifetime.

What is a strength of Bahrick's study?

High external validity because it used meaningful real life memories.

What is a limitation of Bahrick's study?

Confounding variables such as reunions may have refreshed memories.