Radar charts compare multiple numerical variables. They show which variables have similar values, and to spot outliers, high values, and low values. Each variable is provided its own individual axis, but the axes are arranged radially. Every observation connects to form a shaded polygon. • Limit the number of variables to reduce the number of axes to increase readability. • Scaling is affected when variables have dissimilar minimum and maximum ranges.
Sosulski, Kristen. Data Visualization Made Simple (p. 52). Taylor and Francis. Kindle Edition.