Representing data and drawing rules

Graphs, diagrams and maps give a quick visual impression of data, make comparison easy, and save time.

Choose the method that fits the data:

• line graphs for time series (changes over time);
• bar diagrams for amounts like rainfall or production;
• dot maps for distribution (like population);
• choropleth maps for rates and densities.

Choose a scale that is neither too large nor too small for the paper.

Every diagram or map needs:

• a title: the area, the year, and a clear caption;
• a legend (key), usually in the lower left or right corner;
• a north direction arrow (on maps).

Diagrams can be one-dimensional (lines, bars), two-dimensional (pie diagrams, squares) or three-dimensional (cubes, spheres).