Research on Memory Systems: Coding, Capacity, and Duration

This comprehensive page explores fundamental research on memory systems, focusing on three key aspects: coding, capacity, and duration of both short-term and long-term memory.

Definition: Coding refers to the process of converting information between different forms in memory systems.

Coding Research

Baddeley's (1966) research investigated coding differences between memory stores using word lists varying in acoustic and semantic similarity.

Example: In short-term memory experiments psychology, participants performed worse with acoustically similar words in immediate recall, while semantic similarity affected long-term recall more significantly.

Capacity Research

Multiple studies have examined memory capacity:

Highlight: Jacobs (1887) found mean memory spans of 9.3 for digits and 7.3 for letters, while Miller (1956) established the famous "7±2" rule for short-term memory capacity.

Duration Research

Peterson and Peterson (1959) and Bahrick et al. (1975) conducted significant studies on memory duration:

Example: The Short term memory duration research showed decay to 3% recall after 18 seconds without rehearsal.

Highlight: Long term memory capacity study demonstrated 70% photo recognition accuracy after 48 years.

Evaluation Points

The research presents both strengths and limitations:

Vocabulary: External validity refers to how well research findings can be applied to real-world situations.

• Artificial stimuli usage limits generalizability
• Replication of findings strengthens validity
• Recent research suggests STM capacity might be closer to 4±1 chunks
• Bahrick's study demonstrates high external validity through real-world memory assessment