Scatterplots

Another type of data display that can be effectively animated to show changes over time is a scatterplot. This is particularly useful when the crosses represent named items such as countries. It is sometimes possible to identify items whose behaviour in the dynamic scatterplot is different from that of most others.

The effectiveness of the scatterplot for showing information about countries is enhanced if each is represented by a circle whose size describes population or some other measurement that reflects 'size' such as GDP. An extremely good implementation of this methodology is implemented by the Gapminder software.

Birth rate and life expectancy in Africa

The scatterplot below shows the birth rate and life expectancy of all countries in Africa.

Drag the slider and observe:

Click on individual crosses to identify the countries and leave a trace of their progress over the period.

Select Display values as circles from the pop-up menu on the bottom right. This displays each country as a circle whose area represents the country's population. This dynamic display is particularly effective at showing the changing birth rates and life expectancies.