The Three Errors in Standard Deviation Statistics

There are five data points that all belong to the same group of athletes. These are not independent observations. The original paper had done is just treated those as five independent pieces of information. They dumped them into their Pearson's correlation coefficient as if they were five different groups of athletes completely independent. In fact, the correlation in those sprinting measurements was about 0.96. So what you're doing in that case is like quintuple,. but five data points and pretending that you have a much larger sample size than you actually do at all. And then people, you know, not quite understanding that can mix those up very easily.