Apparatus of Galton

Demonstration appliance for statistics

This apparatus has been developed by the mathematician Galton. The appliance is easy as a toy to work with and allows you to get acquainted with statistical concepts of standard distributions. Average, standard deviation, scatter... are all of sudden no longer abstract but clearly visual. Statistics are not a matter of hanky-panky, but scientifically based methods.

How it works

100 coloured balls pass through the appliance. On its journey every ball meets 11 rows of pins where it can choose whether it will go left or right. By moving the dispenser one can set an average, by decreasing the rows of nails, the standard deviation can be adjusted.

It's easy to make the link with the production floor. Every nail can be seen as a haphazard event with two possible outcomes. Let's take the planing of a beam in different stages. In every stage there is a chance that we plane a bit too much or not enough. When we finally passed all 11 steps, we won't be able to predict the exact size of the wooden beam. When we plane a lot of beams the size of all these beams will be distributed as the Galton appliance demonstrates.

With this appliance you can also demonstrate a number of basic concepts of applied statistics in a very simple way such as X-R and Me-R charts, overregulating a process, relation between machine limits and specifications, two-top distribution, Cusum-technique,...

Advantages

• Easy to understand demonstration, no exhausting theoretical deductions but real events
• Demonstrations for larger groups is possible due to the large and brightly coloured balls

Prices

• basic appliance: 745 EUR incl. balls in 2 colours
• protection cover: 30 EUR
• 100 extra balls: 10 EUR (available colours: yellow, green, red, blue, black)