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ERIC Number: ED045469
Record Type: Non-Journal
Publication Date: 1970-Sep-8
Pages: 17
Abstractor: N/A
Reference Count: N/A
The Relative Effectiveness of Some Common Graduated Point Symbols in the Presentation of Quantitive Data.
Flannery, James John
Some general philosophy about maps is presented in the introduction. It is noted that the main purpose of a map is to generate an intellectual response through visual symbols. Quantitative distribution maps present a number of design problems that have led to continuing investigations of graduated circles as point symbols. A summary of the original graduated circle study, by the author, is presented. Six advantages to using graduated circles are summarized, however, map users consistently underestimate size differences when relying on the circle. One thousand forty college students from five colleges were tested and there was 70.5 percent underestimation. Additional tests were given to provide data for the construction of an appartent of visual size curve. Logarithmic transformation and the method of least squares were used to derive an estimating equation for circle tests to convert data into symbolic form. Recent test results, including P.V. Crawford's dissertation on the validation of apparent size scale for graduated circles, are included and generally support the author's research. It is noted that wedges and bars as symbols have some advantages, but that circles are generally preferred. (SLD)
Publication Type: N/A
Education Level: N/A
Audience: N/A
Language: N/A
Sponsor: N/A
Authoring Institution: Queen's Univ., Kingston (Ontario).