Abstract
An important concern for cartographers is in making maps that convey information accurately and efficiently. Because the dot map is a popular method of portraying qualitative data, it is necessary to know how effective the symbolization is in eliciting the desired intellectual responses. This paper investigates whether dot numerosity differences are over or underestimated in a purely map context. An experiment was designed to determine if dot numerosity differences are over or underestimated or if they are perceived accurately. The results of the test indicated that for an area with a given number of dots, comparisons made to areas with a higher number of dots are generally underestimated. Overestimation, on the other hand, was revealed when comparisons were made with areal units containing fewer dots. It has been suggested that numbers of dots be rescaled to decrease perceptual error on dot maps.
Recommended Citation
Butler, Christine L.
(1988)
"The Estimation of Numerosity on Dot Maps,"
The Geographical Bulletin: Vol. 30:
Iss.
2, Article 2.
Available at:
https://digitalcommons.kennesaw.edu/thegeographicalbulletin/vol30/iss2/2
