Deciding How the Data Should Be Mapped

Turning raw data into clear, effective, and accurate maps requires careful attention to detail and strategic decisions about the map design and format. This page provides an overview of the key decisions involved in this process.
Click on the links below for additional technical resources.
  • What geographic boundaries should be used for defining the extent of the map?
  • What geographic unit should be used to display the data (e.g., block group, census tract, zip code)?
  • What mapping format should be used (e.g., heatmaps, shapes, points)?
  • What labels or reference layers should be included in the map (e.g., roads, rivers, boundaries, city names)?
  • How should the data be categorized and classified (e.g., natural breaks, quantiles, equal intervals)?
  • What colors should be used to represent each data class?
  • What symbols should be used to represent the data?
  • Should the map include raw data values? How will they be displayed?
  • What information should the legend include to help users understand the map?
  • What adjustments should be made to ensure the map accurately reflects on-the-ground conditions? (See Challenges and Strategies for Mapping Vector Data for more information.)