Build a sourced map for a geography project

Choose a question a map can answer

Ask where something is concentrated or how it varies across adjoining areas. Choose the area type first: countries, districts or a regular grid. A world map is useful for finding countries. It gives a false impression of precision if you ask which streets are within a ten-minute walk of a library. Write the unit, year and area type before downloading anything.

Match records to boundaries

Use a shared code where possible, such as ISO alpha-3 for countries. Check what each dataset means by an area, since territories and boundary years can differ. Test three matches by hand and list every unmatched or duplicate code. Keep the boundary version or date alongside the indicator year. Read the boundary source’s policy on disputed areas before labelling them.

Choose what the colours express

For a shaded-area map, use a rate if population or land area drives the count. Fictional example: 20 libraries for 200,000 people is 1 per 10,000 people. A district with 12 libraries and 60,000 people has 2 per 10,000. The district with more libraries ranks lower per resident. Show missing data with its own pattern or colour and use the same class breaks in maps you want to compare.

Show enough evidence to redo it

Add a meaningful title, a legend with units and a sentence explaining what the reader should notice. Include the indicator publisher and year, boundary provider and version, and the date you made the map. Place a small table or text summary beside it. Save the input table, the calculation and the editable map separately. Open the finished graphic in greyscale and check that a missing area is still recognisable.

• Colour a map and edit its legend

• Practise with a small dataset