[alain94040]

Actually, I believe he is probably correct in that case. He is discussing whether the mean is meaningful depending on the shape of the distribution. It's probably not fair to summarize his explanation as saying he doesn't understand mean and average.

HN's guidelines recommend to assume the best.

[d1sxeyes]

I would agree that you should always try to assume the best (and I didn't actually suggest he doesn't understand), but he certainly explains it clumsily, and his explanation does not illustrate the difference between a median and a mean, or when one would be more meaningful than the other.

[pkd]

I don't think it's the best explanation, but I do think he understands that mean as a measure of central tendency is not that useful when distributions are skewed or multimodal (the squiggly line gesture).

[d1sxeyes]

Yes but:

1. If data is multimodal (wiggly line), the median isn’t a great measure of central tendency either.

2. Perfectly normally distributed data will have the same mean and median.

I agree people have jumped on this as evidence the guy doesn’t understand when he probably does, but what he says is a long way from the truth.