Maps and the Geospatial Revolution: Lesson 5, Lecture 2
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This document discusses the principles of cartography, focusing on color choice and data classification in thematic maps. It emphasizes the importance of using appropriate color schemes such as sequential, diverging, and qualitative, and warns against the misapplication of rainbow color schemes, which can lead to misinterpretations. Additionally, it covers data classification methods and the challenges of designing readable text on maps.
Maps and the Geospatial Revolution: Lesson 5, Lecture 2
- 1. Maps and the Geospatial Revolution Lesson 5 – Lecture 2 Anthony C. Robinson, Ph.D Lead Faculty for Online Geospatial Education JohnA. Dutton e-Education Institute Assistant Director, GeoVISTA Center Department of Geography The Pennsylvania State University This content is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License
- 2. Choosing Colors • Colors on thematic maps should correspond to the type of data you’re trying to show – Do you have numerical or categorical data? • Color schemes include three major types – Sequential (less -> more) – Diverging (above and below an average) – Qualitative (pizza, currywurst, and tonkatsu)
- 7. Rainbows Kill People • Rainbow (spectral) color schemes are commonly misused on maps – Weather maps showing precipitation amounts – Every “heat map” floating around • They’re bad because they often use qualitative colors to show sequential or diverging data – Is blue more than yellow? Is purple more than blue? • They also can kill people – Doctors interpreting medical images of the heart made worse decisions about their patients using rainbow schemes than simple sequential schemes
- 10. Data Classification • Assigning observations to categories is called data classification • Three major types to know – Equal Interval – Quantile – Natural Breaks
- 14. Text On Maps • Designing text on maps is a major aspect of cartography • Choosing fonts and positioning labels can be a daunting task – Labeling every street, building, etc… and making them all readable together
- 15. Maps and the Geospatial Revolution www.coursera.org/course/maps Twitter @MapRevolution Online Geospatial Education @ Penn State www.pennstategis.com This content is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License