Jacobs found how much information STM can hold using digit span. The researcher read out four digits and the participant had to recall these out loud in the correct order. If this is correct, the researcher reads out 5 digits and so on until the participant is stumped and can't recall them in order. This indicates the individuals digit Jacobs found that the mean span for digits across all participants was 9.3 items, the mean span of letters was 7. 3.
Span of memory and chunking
Miller made observations of everyday practice. He noted that things come in 7s - 7 days a week, 7 notes on a musical scale, 7 deadly sins. Miller thought that the span of STM is about 7 items + or -
2. He also noted that people can recall 5 letters as easily as 5 words. We do this by chunking -grouping sets of digits or letters into units or chunks.
