1. the process by which the mind divides large pieces of information into smaller units (chunks) that are easier to retain in short-term memory. As a result of this recoding, one item in memory (e.g., a keyword or key idea) can stand for multiple other items (e.g., a short list of associated points). The capacity of short-term memory is believed to be constant for the number of individual units it can store (see seven plus or minus two), but the units themselves can range from simple chunks (e.g., individual letters or numbers) to complex chunks (e.g., words or phrases). The exact number of chunks remembered depends on the size of each chunk or the subunits contained within each chunk.

2. the associated principle that effective communication between humans depends on sorting information into units that do not exceed the mind’s capacity to chunk them (the chunking limit). This has implications for the content and layout of written documents, diagrams and visual aids, websites, and so on. For example, any list of more than nine bullet points should normally be subdivided into two or more shorter lists. [coined by George Armitage Miller in 1956]