CCTV cameras

It keeps coming up in the press. I heard it on the radio. Big Brother is watching us. A story the other day about how few crimes are solved by them. Watch 'Spooks' the TV spy program and you would think that your every movement was observed by them. We are told that a third of all the CCTV cameras in the world are concentrated in Britain.

Let me let you into a secret. It ain't true.

What is true is that no-one knows how many CCTV cameras there are in the UK. They are mostly put up by private individuals or firms to protect their property. So where does this paranoia come from.

It comes from a survey done 7 years ago in Putney, south-west London. Observers walked up two streets in Putney, which is an affluent area of London, and counted the number of CCTV cameras they could spot. Then they worked out how many people there were in those streets - about a couple of hundred - divided that number into 60 million, and then multiplied the answer by the number of cameras they spotted.

As an exercise in statistics it was ludicrous, about as silly as a newspaper poll that claimed that more than 50% of doctors approved of something or other. It turned out that the newspaper asked 15 doctors their opinion and extrapolated from that.

It used to be said that 90% of statistics were made up on the spot. That probably isn't true, but the abuse of statistics is very common perpetrated by people who ought to know better.

One site to visit if you want to know more about statistics is this

I listen to the pod cast regularly and it never fails to explode silly statistics.