Vladimir_Nesov comments on Open Thread, April 27-May 4, 2014 - Less Wrong Discussion
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After a contribution to a previous thread I thought some more about what I actually wanted to say, so here is a much more succint version:
The average of any distribution or even worse of a dataset is not a sufficient description without a statement about the distribution.
So often research results are reported as a simple average with a standard deviation. The educated statistician will recognise these two numbers as the first two modes of a distribution. But these two modes completely describe a distribution if it is a normal distribution. Though the central limit theorem gives us justification to use it in quite a number of cases, in general we need to make sure that the dataset has no higher modes. The most obvious case is of a dataset dominated by a single binary random variable.
This statement then, that not all datasets are normally distributed, holds for any field, be it solid state physics, astrophysics, biochemistry, evolutionary biology, population ecology, welfare economics or psychology. To assume that any average together with a standard deviation derives from a normal distribution or even worse that there is no more information in the dataset or the underlying phenomenon is a grave scientific mistake.
(The "only if" is incorrect. For many other families of distributions, knowing mean and variance is also sufficient to pinpoint a unique distribution.)
I must have mixed it up with some other statement.
"Yeah, sorry I said something that was incorrect. I meant to say something that wasn't incorrect."
I've seen more ballsy responses than this, but not many.
I don't understand. Metus flatly admitted error, end of story.
For clarity, I found what Metus said to be very funny. I commented because I wanted to underscore the humour, not because I wanted to be critical.
FWIW, I also read it as an insult. And though I do believe you that that wasn't your intent, I don't see how else to read it even now.
Well, it wasn't intended as a kind comment either, but it clearly fell a lot flatter than I thought it would.