Digit span
Measure how many digits you can hold in mind for a few seconds and repeat back in the right order.
Method
Procedure
- Digits appear one at a time, a new digit every second.
- When the sequence ends, type the digits in the same order and press Submit or Enter.
- The first sequence has 3 digits, and each correct answer adds one digit.
- The experiment ends after two wrong answers in a row at the same length, or after 12 digits.
Responses
- 0 to 9
- type the digits
- Enter
- submit your answer
- Touch
- the number keyboard and the Submit button
Measures
Your digit span: the length of the longest sequence you repeated correctly. It is a measure of how much can be held in short-term memory when the items can be repeated silently.
Practice
Two practice sequences of three digits tell you after each one whether you typed it correctly.
Terms
- Working memory: The system that holds a small amount of information in mind for a few seconds while it is used.
- Span: The longest list that can be repeated back correctly.
- Chunk: A group of items remembered as one unit, such as 1-9-8-4 remembered as a year.
- Rehearsal: Repeating items silently to keep them in mind.
- Prefrontal cortex: The front part of the frontal lobe, involved in working memory.
Experiment
Responses stay in this browser tab. Nothing is stored or sent, and everything is lost when the page is closed or reloaded.
Results
Interpretation
The procedure allows a second attempt at the same length, because a single error can occur by chance. Grouping the digits, for example into pairs, usually helps; if you did that, your span reflects chunks as well as single digits.
Comparison with published studies
Miller (1956) reported an immediate memory span for items such as digits of about seven, plus or minus two.
Limitations
Each length is tried once, or twice after an error, so the estimate is coarse and can differ between sessions. The digits are shown on the screen and typed, so the value is not directly comparable with tests in which digits are spoken. It is not a clinical or intelligence test.
The result comes from one person in one session, on a device whose timing and display are not calibrated. It describes this run, not a stable characteristic of the participant, and a second run could differ by chance alone. Research studies test many participants under controlled conditions and report the average with its variability. The experiment is educational; it is not a test of ability or health.
One row per attempt: length, the sequence shown, what you typed and whether it was correct. In the file, 1 means yes and 0 means no. The file is created on this device and can be opened in a spreadsheet.
Background
Original findings
Miller (1956) summarised evidence that people can hold about seven items in immediate memory, “seven, plus or minus two”. Later work suggests that the underlying capacity is closer to three to five items, or chunks, when repeating and grouping the items is prevented (Cowan, 2001). Digit span is usually longer, because digits can be repeated silently and grouped, as in a telephone number.
Neural basis
Holding information in mind for a short time, known as working memory, depends on networks in the prefrontal cortex and the parietal lobe.
References
- Miller, G. A. (1956). The magical number seven, plus or minus two: some limits on our capacity for processing information. Psychological Review, 63(2), 81–97. https://doi.org/10.1037/h0043158
- Cowan, N. (2001). The magical number 4 in short-term memory: a reconsideration of mental storage capacity. Behavioral and Brain Sciences, 24(1), 87–114. https://doi.org/10.1017/S0140525X01003922
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