How does the Operation Span Test work?
Each step shows a sum with an answer, such as (6 ÷ 2) + 4 = 7, and you say whether it is right, within 6 seconds. Then a letter shows for 1 second. After 3 to 7 of these, you tap the letters back in the order they came. There are 5 sets, one of each length, in a random order, so you never know how many letters are coming.
The letters come from 12 consonants, F, H, J, K, L, N, P, Q, R, S, T and Y, and no letter appears twice in a set. When you recall, Blank keeps a place for a letter you can't remember, so the ones after it can still land in their own places; Undo takes back the last tap. A sum you don't answer in time counts as wrong, and its letter comes anyway.
How is the Operation Span Test scored?
Your score is the number of letters you recalled in their right place, out of 25. Getting 4 letters of a 5-letter set in place scores 4, not 0, so every letter counts. Order matters: the right letters in the wrong places score only where they happen to land. Tapping letters at random would put about 2 of the 25 in place.
Beside it are your perfect sets, the longest set you recalled in full, and the share of sums you got right. If fewer than 85% of the sums were right, the result says so: a high letter score bought by ignoring the sums is a plain memory span, not an operation span. Andrew Conway and colleagues' guide to span tasks (2005) discusses how tasks like this are given and scored.
What is operation span?
Operation span is a complex span task: it measures how much you can keep in mind while your attention is busy with something else. Marilyn Turner and Randall Engle introduced it in 1989, after the reading span task of Meredyth Daneman and Patricia Carpenter (1980), which paired reading sentences with remembering words.
Nash Unsworth, Richard Heitz, Josef Schrock and Randall Engle (2005) made an automated version that scores itself. Its scores held steady when people took it again (a test-retest reliability of .83) and went with measures of fluid reasoning. This test is a recreational version with its own sums, timing and length, and it gives no diagnosis.
Why does the Operation Span Test have sums?
To stop you rehearsing. With nothing between the letters, you could repeat them under your breath, and the test would measure a simple span like the Digit Span Test. The sums take that time away, so what you recall is what you held while thinking about something else. That is why the time limit is short and why the sums are scored too.
What can affect your Operation Span score?
How you split your attention, most of all: rushing the sums to rehearse costs sum accuracy, and lingering on them costs letters. Arithmetic that feels hard leaves less room for the letters, and a set of 7 after a set of 3 can catch you out. Practice helps too, as with any task. For another way to hold and update at once, try the N-Back Test or its two-stream form, the Dual N-Back Test.
What doesn't the Operation Span Test measure?
It isn't an IQ test or a clinical assessment. Research versions differ: more sets, a time limit set from each person's own practice speed, and different letters and sums, so a score here can't be set beside one from a study.