Forward digit span · two attempts per length

Seven Things

A sequence flashes one digit at a time. You type it back. Every round it gets one longer, and it does not stop until you miss twice at the same length. Say now how far you think you will get.

The test

Card 01 · instructions —

First, a prediction

How long a string of digits do you think you can hold, seen once, at one a second, with nothing to write on?

10
315

Nobody sees this but you. Be optimistic if you like — most people are.

 
Watch the card
— digits held

you
35791113

Shaded band: the five-to-nine range that healthy adults usually fall in, median around six or seven.

Twelve digits

Longer than anything you have just failed at. It will not be shown one digit at a time.

 
 

About This Test

Seven Things is the forward digit span task, which is roughly as old as experimental psychology and still the most used measure of short-term memory in clinical practice. Digits appear one at a time, you type them back in order, and the string grows by one every round. Two attempts per length; miss both and you are done. It takes about three minutes and it is unusually bad at flattering people.

The prediction at the start is the point of the whole thing. Almost everyone sets it around ten or twelve, because ten or twelve digits does not sound like very much — it is a phone number, and you have been reciting phone numbers your entire life. Then the cards start coming and something goes badly wrong around eight, in a way that feels less like forgetting and more like the floor giving way.

Where you land is likely to be five to nine, with most people at six or seven. That is the population range, not a verdict: single-session scores on a web page are noisy, the spread among perfectly healthy adults is enormous, and nothing here is a calibrated measurement of anything. What it is good for is the shape of the failure, which is remarkably consistent and which the final round explains.

How To Play

  1. Set your prediction honestly. You will want to revise it afterwards and you will not be allowed to.
  2. Watch the card. Do not write anything down, and do not photograph the screen, obviously.
  3. Type the digits back in the order they appeared, using the keypad or your keyboard.
  4. Two attempts at each length. Passing either one takes you up.
  5. When you break, do the last round. It is the only part of this that will change how you think.

Why This Exists

Because the most famous number in psychology is wrong, and the interesting part is how it is wrong. In 1956 George Miller published a paper on the magical number seven, plus or minus two, and it became one of the most cited things ever written about the mind. Seven items. It is on every undergraduate syllabus and in every design textbook, usually as an instruction to keep menus short.

Miller's actual insight was subtler and got flattened in the retelling. The unit of memory, he argued, is not a piece of information but a chunk — and a chunk can be anything you already recognise. A phone number is one chunk. A word is one chunk. A chess position that a novice sees as thirty-two separate pieces is a handful of chunks to a grandmaster, which is why they can glance at a board and reproduce it. Seven chunks can hold almost nothing or almost anything depending on what you have learned to see.

In 2001 Nelson Cowan pulled the number apart properly. Miller's seven, he pointed out, was offered as a rough estimate and a rhetorical device rather than a real capacity limit, and once you build a task where people cannot rehearse or group the material, the figure collapses to three to five. Four is what you get with chunking blocked; seven is what you get with chunking free. So your score here was never a measurement of storage. It was a measurement of how good you are at inventing groups under pressure — which is exactly what the last round proves by handing you twelve digits you can hold effortlessly. The debate is not closed, and serious people still argue for five or even seven. But nobody thinks any more that you are holding seven separate things.

Frequently Asked Questions

What is Seven Things?

It is the forward digit span task, the oldest and most used measure of short-term memory in psychology. Digits flash one at a time on a card and you type the sequence back. Every round is one digit longer. You get two attempts at each length, and the test ends when you miss both.

What is a normal score?

Forward digit span in healthy adults usually falls somewhere between five and nine, with the median around six or seven. Nine or ten is above average and eleven upwards is genuinely unusual. The spread is wide enough that no single number tells you much, which is one reason a one-off score on a web page should not be read as a measurement of anything.

Why is it called Seven Things?

After George Miller's 1956 paper on the magical number seven plus or minus two, the most famous figure in cognitive psychology. The joke of the title is that the number is not really seven. Miller himself meant it loosely, and the last round of this test demonstrates why.

So what is the real capacity?

Closer to four. Nelson Cowan's 2001 review argued that Miller's seven was intended as a rough estimate and a rhetorical device rather than a hard limit, and that the true figure is three to five chunks. The difference comes down to chunking: about four is what you get when neither rehearsal nor long-term memory can be used to group items, while seven is what you get when grouping is unrestricted. Not everyone agrees, and estimates from five up to seven are still defended.

Why do I do better when the digits are grouped?

Because a group becomes one item. Miller's real insight was that the unit of memory is a chunk rather than a piece of information, so a phone number, a word or a familiar chess position each takes up a single slot no matter how much is packed inside it. Anyone who scores nine on this test is almost certainly holding three groups of three rather than nine separate digits.

Does it work on mobile?

Yes. There is an on-screen keypad so nothing depends on a physical keyboard or on autocorrect behaving itself, and a hardware keyboard works too if you have one. Nothing is saved or uploaded, and there is no score to beat but your own.

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