Gray Tone Versus Line Plotter Area Symbols: A Matching Experiment
Authors: Slocum, Terry A.; McMaster, Robert B.
Source: Cartography and Geographic Information Science, 1 April 1986, vol. 13, no. 2, pp. 151-164(14)
Abstract:Gray tones and line plotter shades are two common area symbols used to display quantitative data on maps. Since these two symbols are visually quite different from one another, the question arises as to whether or not the overall spatial message communicated by maps using these symbols would be identical for a particular data set. As a preliminary to answering this broader question, an experiment was performed in which subjects matched individual line plotter shades with gray tones. The purpose of this experiment was twofold: 1) determine the general relation between the two symbol types, and 2) determine the ease with which line plotter symbols could serve as substitutes for gray tones. The results revealed first that the general relation is essentially linear; a gray tone of a given percent area inked can be represented by a line plotter shade of about the same percent area inked. As such, the results support those obtained in previous gray scale studies. Secondly, both the actual response data and comments provided by subjects indicate that line plotter symbols are difficult to match with gray tones. This difficulty may portend differences for the overall spatial message communicated by these two symbol types.
Document Type: Research Article
Publication date: April 1, 1986