What a share hides when its count is missing
A share is two numbers and you were shown one of them, so the useful move is to ask for the other one.
Every share is two numbers. Somebody worked out how many cases came back right, and divided it by how many cases there were. You were shown the result of the division and not the number underneath it, and the number underneath it decides how much the share is worth.
Here is the whole of the arithmetic, and it is arithmetic you can do in a meeting. Fifteen right out of sixteen cases and a hundred and fifty right out of a hundred and sixty cases are the same share. The first could comfortably be hiding a true ability of anywhere from about two thirds to nearly everythingmodeled: fifteen right out of sixteen cases, and nothing else assumed. The second could not.
You do not need to know how that range is worked out. You need to know that it exists, that it is wide when the count is small, and that the count is the thing left off the slide.
Why this did not make the three
It is the most frequently violated question in this volume. Almost every result that circulates is a share with no count attached. And it still came fifth, for a reason worth stating plainly rather than hiding.
The answer is a number, and a number on its own rarely changes what you do. Told the count was small, you conclude the result is thin — which you could have guessed. Told it was large, you conclude very little, because a large count over the wrong cases, or with the failures quietly removed, is worth no more than a small one. The question in the next step is the deeper version of this one, and it is the one that made the list.
The bad answer to watch for is a big count that arrived suspiciously fast. A large set of cases is expensive to build when somebody has to decide what the right answer is for each one. A very large set that appeared quickly usually means the right answers were generated rather than determined, and then you are measuring agreement with a guess.