Let's hear your horror stories - what glaring and substantial errors have you found while reviewing others' stats?

Let me kick this off with a real nice doozy I found tonight!

I'm reviewing a multinomial logistic regression when I see a rather suspicious line of code.

They're assigning labels to the levels of a factor, and and then assigning that output to a column. Turns out that the way they did it, they overwrite the entire data with a repeating string of 0, 1. Instead of 1000 0s and 300 1s like the true data, we now we …

datascience errors horror