I call myself a statistician, because, well, I’m a statistics graduate student. However, ask me specific questions about hypothesis tests or required sampling size, and my answer probably won’t be very good.
The other day I was trying to think of the last time I did an actual hypothesis test or formal analysis. I couldn’t remember. I actually had to dig up old course listings to figure out when it was. It was four years ago during my first year of graduate school. I did well in those courses, and I’m confident I could do that stuff with a quick refresher, but it’s a no go off the cuff. It’s just not something I do regularly.
Instead, the most important things I’ve learned are less formal, but have proven extremely useful when working/playing with data. Here they are in no particular order.