The NAG board

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Galton
board

This looks exactly like a Galton board.  (If you haven’t read about this yet, go and do it – this page will make more sense.) So why the different name?
It’s fairly simple – a Galton board is a thought experiment, an ideal world. Not real.

If you actually get a piece of board and knock nails into it, to make an actual board that you can roll balls down, you are no longer in the world of thought and ideals – even it it looks just like a Galton board. Here are a few reasons why.

[Bullet list with a nail graphic for each bullet]

  • It’s impossible for a person to knock in every nail at exactly the same angle.
  • No one could get every nail in exactly the correct position on the board – and even half a millimetre could make a difference.
  • There are lots of different types of ball – some are harder or heavier than others – and some are really bouncy. The kind of ball will have an effect on the way it behaves when you drop it into the board.

So this is why we call it a NAG board – it looks like a Galton board but it is Not A Galton board.

Watch the video to see what happened when we tried it out. [Video 5V]

You can play the same sort of games as you can with the Galton board. [links to Games 1b and 2b]

So what does it all mean?

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What’s the
point?