African calorie intake in 1993 and 1998

Use this diagram to explain that it is important to think carefully about what variables to display or analyse. Sometimes a ratio or difference between variables is more meaningful.

Select 1993 cals and 1998 cals from the pop-up menu to display these variables on the map. The maps highlight effectively highlight places with worst nutrition. However a different aspect of the data can be seen by defining a new variable %Increase:

%Increase   =   100  ×   1998 calories − 1993 calories
1993 calories

Select %Increase from the pop-up menu to see which countries have improved their calorie intake between 1993 and 1998.

(Also see the other related examples in the General and Business versions of this page — click the triangle at the top right of this page to select alternative versions of any page.)