chunking

Meaning: Chunking is an encoding strategy that combines separate items into larger meaningful units, such as remembering 1-9-4-5 as one year instead of four digits. Working memory is limited in the number of units it holds, not in the amount of information inside each unit. Miller's classic estimate is about 7 ± 2 chunks; later work suggests a smaller number, often near four. What counts as a chunk depends on long-term knowledge, so a chess expert sees a board as a few patterns where a novice sees many separate pieces.

On the MCAT: A passage describes a recall task in which one group gets grouped or familiar items (FBI, CIA, USA) and another gets random strings. Predict better recall for the grouped list. Expert versus novice designs are common: experts recall real game positions better than novices, but the advantage largely disappears for random arrangements, because those cannot be chunked using stored knowledge.

Common confusion: Chunking does not increase the number of slots in working memory; it packs more information into each slot. It also differs from maintenance rehearsal, which is simple repetition to keep items active and does not reorganize them into meaningful units.