Daily Archives: 2nd January

Resolution and Strictly Come Dancing

The television programme, Strictly Come Dancing, can be used to demonstrate the concept of resolution.

Normally there are four judges on the show, but towards the end of the run the number of judges was increased to five with the addition of ballerina Darcey Bussell.

So why was Darcey Bussell added?

At the beginning of the show there are 16 couples, of varying ability. There is therefore likely to be wide variation in the judges’ scores. Towards the end of the show, after the lower-ability couples have been removed, there is far less difference in their performance.

For example: in Week 3 the difference between the highest and lowest score was 16 points out of 40 (40%). In Week 14 (the final week) the difference between the higest and lowest scores was 4 points out of 200 (2%).

The addition of Darcey Bussell as a fifth judge increases the resolution of the scores. With four judges the biggest possible difference between two couples is one-fortieth (0.025) of the total; by adding a fifth judge the resolution becomes one-fiftieth of the total (0.020).

Imagine trying to measure the length of some unknown object. Would your measurement be more accurate if your measuring stick was divided into forty segments, or fifty? The greater the number of segments, the more accurate the measuring stick.

Source: Strictly Come Dancing (Series 7) from Wikipedia.