Why I can't have conversations using Twitter
Re: the original convo, they're stuck on the fact that arithmetic mean isn't terribly valid on a skewed distribution (and response/completion distributions are generally positive-skewed because of the firm/hard lower bound on task completion).<p>However, I do get what you're trying to do re: identify whether the problem is related to outliers. But in general, comparing to median has a lot more validity. Median isn't as sensitive to skew, and will be closer to the peak. For your purposes it probably wouldn't be a lot different but you wouldn't have pushed the "it's wrong" button.<p>All said, though, even comparing 50th (median) to 99th is pretty coarse. I'd probably be looking somewhere closer to 75th percentile for a comparison. Basically, you'd want to guess what percent might reasonably be affected by performance spikes and compare from there.