Wednesday, 14 May 2014

Lies, damn lies, and statistics (British Gas)

I did statistics at school (yes, proper stats O level!).

But when I see crap like this I do not really know what to say.

One thing you really should avoid doing is using a false origin when showing something graphcially.

There are circumstances where the absolute level is unimportant and the relative scale over many things can be shown on a false origin, maybe, but not this case.

This is a simple "how does your gas use compare to last year", and shows last year and this year in some graphical way.

I looked and thought:

  "shit, we are using twice as much gas this year, WTF!".

Then I realised the coloured bars were meaningless. In fact we have used 0.84% more gas. Drawn on a true origin, that would have been obvious, and no surprise.

Why even have the coloured bars?

The electric summary is just as bad - looks like we have halved our electric usage when in fact it is down only 12% (though that is not bad).

Sadly both of these are based on estimated readings, so pretty worthless, and rather pointless sending me the summary (in two separate envelopes).

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