Digit span test
Digits appear one at a time. When they stop, type them in the same order. Each time you get it right the run grows by one digit. Two misses at the same length end the test.
| Your span | – |
|---|---|
| Longest run shown | – |
| Your best span on this device | Not yet played |
What this measures
This is forward digit span: how many digits you can hold and repeat in order after one look. It is among the oldest and most widely used tests of short-term verbal memory, and has been part of the Wechsler memory scales for decades.1
It measures one narrow thing. A long span is not a high IQ, and a short one is not a low one.
What is a typical span?
One study gave a computer-run digit span test to 763 adults aged 18 to 65.1
| Measure | Average |
|---|---|
| Forward span | 6.5 digits |
| Longest run repeated correctly | 6.8 digits |
| Backward span, digits repeated in reverse order | 4.9 digits |
Forward span showed no reliable link with age across that range. The digits in that study were spoken through headphones. Here they are shown on a screen, so treat the figures as a rough guide.
Seven, plus or minus two?
The best-known figure comes from a 1956 paper by George Miller, who noted that people can hold about seven items, give or take two.2 Miller also described the trick behind long spans: grouping items into chunks, as you do with a phone number.2 A 2001 review argued that when grouping and silent rehearsal are prevented, the limit is nearer four chunks.3
What practice does
Play this a few times and you will probably do better. That is practice at this one task. A 2016 review of the research found that brain training improves performance on the tasks that are trained, with little evidence that it carries over to everyday thinking.4
Sources
- Woods, D. L., Kishiyama, M. M., Yund, E. W., Herron, T. J., Edwards, B., Poliva, O., Hink, R. F., and Reed, B. (2011). Improving digit span assessment of short-term verbal memory. Journal of Clinical and Experimental Neuropsychology, 33(1), 101–111. doi.org/10.1080/13803395.2010.493149
- 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. 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. doi.org/10.1017/S0140525X01003922
- Simons, D. J., et al. (2016). Do "brain-training" programs work? Psychological Science in the Public Interest, 17(3), 103–186. doi.org/10.1177/1529100616661983
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