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Definition
| directly proportional scaling of area or volume of symbols to data values |
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Definition
| in psychological theory, a neutral reference point on which perceived judgments are based; affected by the perceptual anchors from which judgments are made |
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| the size of the visual anchor affects the estimates of magnitude of an unknown symbol; the contrast effect causes estimation to be away from the anchor, and the assimilation effect causes judments to be toward the anchor |
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| Apparent Magnitude Scaling |
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Definition
| scaling of proportional symbols that incorporates correction factors to compensate for the normal understimation of a symbol's area or volume |
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Definition
| in the literature and classic sense, refers to any of the scaled point symbol mapping schemes; with GIS implemntation impolies range grading using ordinally scaled symbols |
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| proportional Midpoint Range Grading |
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Definition
| variation of the range grading in which symbols are in proportion to the midpoint of a class range |
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| Proportional Point Symbol Mapping |
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Definition
| type of quantitative thematic map in which point data are represented by a symbol whose size varies with the data values; areal data assumed to be aggregated at points may also be represented by proportional point symbols |
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Definition
| traditional cartography and modern GIS term that describes symbols that are in true proportion to their attribute data; in GIS usually associated with absolute scaling, and in some GIS software, apparent magnitude scaling |
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Definition
the mathematical expression that describes the relationship between stimulus and response; gener for is R-K*S where R is respons, S is stimuls and K is a constant
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Definition
| a symbol represents a range of data values; differently sized symbols are chosen for differentiablity for each of several ranges in the series of values being mapped; larger symbols indicate more of a quantity but are not in true proportion to the data tey represent |
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Term
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Definition
| expressing the same variable by more than one visual variable; in proportional symbol mapping, the symbol's fill will change in saturation and/or value in proportion to the data that scale the symbol's size; larger symbols have a lighter or less saturated fill |
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Definition
| too much information in a symbol, so that readers have difficulty making assessments about the quantitative nature of the data. |
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Term
| Three-dimensional point symbol |
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Definition
| any point smbol made to appear three dimensional, such as a sphere or cube |
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