## Tuesday, 10 July 2012

### Vorsprung durch technik bias

Unlike the ground-breaking height experiment, this one is complete speculation (and also: no disrespect to anybody, irrespective of the car you drive).

But: while riding my Vespa around London, I've been noticing that, in general (and I'll put this as mildly and unassumingly as I possibly can), Audi drivers are terrible.

What I mean is that if I think of all the drivers I encounter in my daily one-hour ride to and from work, the ones that I remember speeding, cutting everybody else to get in front at a traffic light and unnecessarily moving to the right while I'm filtering to make it more difficult for me seem to be driving an Audi $-$ I've not got enough data to work at the actual model level, so for the moment I'll concentrate on makes.

I have to admit that I thought of this on my way back earlier today, after seeing one of them nearly causing a multiple crash and then speeding through an amber-turning-red traffic light. Thus, of course I know that every possible known bias effect is present here.

As soon as I realised that (which thankfully was just $\varepsilon \rightarrow 0$ seconds later), I tried to think carefully to see if I could remember any other instance of repeated bad driving by a particular brand of cars and, for the life of me, I could not think of any!

The power of recall bias...