Thursday, 18 February 2010

A normal distribution

Hey I am going to unashamedly nerd-out today!!!! Especially as my sister has gone on holiday.

When I did A level Maths, half of it was statistics. I didn't much like it but I found it easy. (Have I mentioned I got an A??!!?? - not bad for someone who could barely read. I am proud that I was once clever in a way people wouldn't suspect to look to me.)

However, there was one concept from stats that really stuck with me: the normal distribution. To me, it is a beautiful and simple concept and I am a concept freak!
I am sure lots of you will have encountered a normal distribution (and some of you reacted badly to it that is if you haven't obliterated it from your grey matter) but it basically shows the distribution of any continuous (not discrete) data such as intelligence, height, foot length, etc in our species. So what it means is you get a greater number of people with or close to the mean average of anything. So if the average height for women was 5 ft 4, then most people would be that height. The further away from the mean you go..i.e. really tall or really short, the less incidence of it there is.

I think it also works for attitudes in that there can be a 'mean' attitude towards something. It kind of explains the conforming thing going on. You get more people behaving 'averagely' than not and the more you venture from 'Joe and Josephine' Normal (whatever they are like) the more you will find yourself in a minority. Obviously the mean average can move, and 'conforming' in one era of history will look quite different from another.

I have used it speculatively to question societal views such as attitudes towards difference and diversity. We know extreme behaviours occur in terms of racism for example. I know extreme stories are very newsworthy so we end up with a worldwide distillation of such stories which can put their prevalence out of perspective. But if these stories represent the extreme...where is the mean and in which direction is it moving? (I think it's moving slowly and surely in the right direction in the UK - first sexism started to be tackled, then racism, then homophobia....on to more) etc etc

You still with me?

But the most interesting thing I learnt about normal distributions was through health promotion. In the past people believed that targeted work was the way to stop extreme risk taking when it comes to health. In other words, for example, with substance misuse (drug taking) work was mostly directed only towards those that were addicted to hard drugs. However, what has been discovered is, while that work is worthwhile as those people need support, overall the best way to tackle such issues is to 'move the mean'. In other words, you teach everyone to change their attitudes towards drug misuse so that the 'mean' attitude changes.

When you move the mean, what they discovered was, you move the extremes too.

As I write this I am amazed by my nerdiness. Please forgive me, I can paint nice pictures too.


  1. I've got to confess that I only read the opening sentence. I know you don't watch much telly but did you see the Channel 4 programme, Dispatches, the other evening. It featured how maths is being taught in schools and it also showed a maths expert with a new way of teaching this. I'm proud to say he and his wife are friends of mine and I'm wondering how many people I know actually saw the programme.

    As for my maths ability - I was rubbish at school but top or almost top for English - two extremes really,

  2. Ah...did my post evoke maths blindness THAT quickly?

    I sneaked this nerdy post in because i had to get the normal distribution out of my system!

  3. You are way beyond me Molly P. I looked at the pictures though...sorry, diagrams.

  4. Hope your sister gets back soon. lol.

  5. Hehe, maths nerdery. Love it. :)

  6. Yep, where's Claire when you need someone to take the p*ss...

  7. This has completely changed my attitude towards drug use.

  8. That's really interesting (genuinely, I did A level pure & stats too!). This is what gets me about the Level 4 target for Y6. What was originally set as the mean is now the expected bottom end of a normal distribution. WTF?!

    I'm also a big fan of the binomial distribution and you can't beat a good Poisson!

  9. I can see my followers are split!!!! Nothing like a good nerding to sort the abstract weidos from those living on Earth.

    Andy - bless you!!!
    Mr T - don't worry, they'll be time for retrospective p taking along the lines of 'I turn my back for one minute...and'
    Clipster - you made me blast laugh with that!
    Nikki - the overlap on our Venn diagram is huge!

  10. I am back and I read it (all). Thoroughly approve. Can't get enough of that stuff.

  11. Was that a ironic doubleback - disguised start - comment?


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