The anecdata that tau is helpful to learners is, IMHO, pretty strong at this point. Facts beat theory. And since anecdata is all we have, well, it&#x27;s all we can use to talk about.<p>I think it&#x27;s way, <i>way</i> too easy for people on the terminal end of education to forget just how easy it is to get tripped up by very, very little things. Especially if they were themselves &quot;good at math&quot; and really aren&#x27;t bothered by extra factors of 2 flying around. This is not the normal experience.