Digit span test
Watch a string of digits, then type it back. The longest string you get right is your digit span, one of the oldest measures in psychology.
- Measures
- Verbal short-term memory span
- Template length
- about 4 minutes (6 sequences)
Digits appear one at a time. When the sequence ends you type it back in the same order. Sequences get longer as you go, from 3 digits up to 8.
The longest sequence you can recall correctly is your forward digit span. It appears in most intelligence and neuropsychological batteries because it is quick, needs no equipment and is sensitive to attention and verbal short-term memory problems.
Try it yourself
A shortened run of the same template researchers use. Nothing is recorded and you do not need an account.
How the task works
- 1Each digit is shown for 0.9 seconds, with a 0.3-second gap.
- 2At the end of each sequence, type the digits in order and press Submit.
- 3The template shows one sequence at each length from 3 to 8.
What people usually find
Adults usually recall around six or seven digits forwards, the origin of the "seven plus or minus two" rule of thumb. Spans backwards are usually one or two digits shorter. Later work suggests the underlying capacity is closer to four chunks, with rehearsal and grouping stretching it further for digits.
How to score it
- Span: the longest length recalled perfectly.
- Total correct: the number of sequences recalled perfectly, which uses more of the data and is usually more reliable than span alone.
Before you run it
- Clinical versions give two sequences per length and stop after both are failed. The template gives one per length and does not stop early, which suits quick online screening but gives a coarser score.
- Typing lets people use the keypad as a memory aid. Visual presentation also differs from the spoken version used clinically, so do not compare scores against clinical norms.
Run it as a study
Use the template as it is
The demo above is the same code as the Digit Span (Forward) template in the gallery. Add it to a project, change the settings in config.js, publish it and share the link. Reaction times and responses come back to your dashboard.
Create a free account to use itOr build a variant: run forward and backward span with a stopping rule
Paste this into the AI panel in the experiment editor. Read the code it writes before you collect anything.
Build a digit span task with a forward block and then a backward block. In each block, start at 3 digits and give two sequences at each length; move up a length if at least one of the two is correct, and end the block when both are wrong or after length 9. Show each digit for 1000 ms with a 250 ms gap, never repeat a digit within a sequence, and collect the answer in a text box that accepts digits only. Record block, length, sequence, answer and whether it was correct, and compute the span for each block.
Common questions
What is a normal digit span?
Forward spans of about six or seven are typical in adults, and backward spans are usually one or two shorter. Norms depend on the exact procedure, so compare within your own sample.
What is the difference between forward and backward digit span?
Forward span mostly measures how much you can hold. Backward span also requires rearranging the items, so it leans more on working memory.
Can I use this as a clinical test?
No. It is a research version with visual presentation and typed answers. Clinical assessment uses standardised, normed tests given by a trained examiner.
References
- Jacobs, J. (1887). Experiments on "prehension". Mind, 12(45), 75–79.
- 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.
- 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.