This person has no idea what they're writing about. Edited because my post was flagged (I'm not sure why). The definition of correlation coefficient is incorre

This person has no idea what they're writing about. Edited because my post was flagged (I'm not sure why). The definition of correlation coefficient is incorrect, which could have been attributed to a typo, except the author goes on to say "The bottom is, essentially, just stripping the signs away.", suggesting the square root of a sum of squared differences would be the same as the sum of differences, were it not for the signs. That's not how norms work. The whole paragraph on interpreting a correlation coefficient is particularly painful to read: "... if the correlation is perfect – that is, if the dependent variable increases linearly with the independent, then the correlation will be 1. If the dependency variable decreases linearly in opposition to the dependent, then the correlation will be -1. If there’s no relationship, then the correlation will be 0." For all its good intentions, I feel like this post hurts more than it helps.