# 2 Different F1-Measure to calculate clustering performance - which one is correct and why?

I know it sounds incorrect but that is the truth

Here let me show you

This below one is the first one and very widely used in the literature

First one reference : Steinbach, Michael, George Karypis, and Vipin Kumar. "A comparison of document clustering techniques." KDD workshop on text mining. Vol. 400. No. 1. 2000.

And the second one is this one : http://nlp.stanford.edu/IR-book/html/htmledition/evaluation-of-clustering-1.html

• At the end of your first page, it says $F_\beta = \frac{(1+\beta^2)PR}{\beta^2P + R}$, which, for $\beta = 1$, is the $F_1$ score. This is the $F_\beta$ score, a generalization (see Wikipedia). What did you mistake for the $F_1$ score in your link? – Winks Mar 30 '16 at 21:37