Ugh, right from the get-go, Rubinstein throws away any attempt at statistical rigor by using an outlier example to try to prove something. The 5% groupings doe

Ugh, right from the get-go, Rubinstein throws away any attempt at statistical rigor by using an outlier example to try to prove something. The 5% groupings doesn't evaluate the metric. It just means that if they plan to use this actual study as a guideline, they should use the same technique in grouping teachers.