Speaking on Newsnight, he said:
"Our standards should be higher. What that in effect means is something like one in five children in primary schools at the age of 11 are leaving primary school without the national average. What that really means is that they can't access the curriculum in secondary school, they find it difficult to pass examinations, they find it difficult to proceed to the next stage of their education and training, and of course they find it difficult to get jobs."
The context of his comments was a damning report by his Office on the standards of English in schools. Of course, all OfSTED reports are damning. That is their style. They are the policy equivalents of radio shock jocks: 'you're useless'; 'you're incompetent'; 'you can't read well enough'.
Sir Michael has taken on this mantle rather well, and clearly enjoys telling parents how hopeless their children's schools and teachers are. The Newsnight interview was a classic example.
But this time, rather like a headteacher farting in the middle of assembly, Wilshaw tripped:
".. one in five children in primary schools at the age of 11 are leaving primary school without the national average .."
Just is case you went to the same school as Sir Michael, let me explain: there will always be children performing below average. Average is a measure of central tendency; it measures the middle value of a collection of data.
Most commentators have been quite forgiving of Wilshaw's error, and have accepted the official explanation that it was a slip of the tongue. I suspect that is because most of them are arts graduates, for whom numbers are fearsome strange beasts.
But this really is not a complex idea. Most Primary School children would understand it. On a good day, my cat gets it.
As the Guardian's
.. if "good" requires pupil performance to exceed the national average, and if all schools must be good, how is this mathematically possible?
By getting better all the time.
So it is possible, is it?
It is possible to get better all the time.
Were you better at literacy than numeracy, Secretary of State?
I cannot remember.
Mr Gove looks like a Muppet that's been given to the dog as a chew-toy. But looks are deceptive. He is clearly made of stronger stuff. His comments here give us a clue to his origins, as a small boy in far-away Lake Wobegon where "all the women are strong, all the men are good looking, and all the children are above average".