Jacques Bertin: Semiology of Graphics
Relevant notes taken from throughout Bertin’s book covering all areas of information visualisation.
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“…graphics is one of the major “languages” applicable to information processing” (p.2)
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A monosemic system: when the meaning of each sign is known prior to observation. Bertin describes graphics as monosmic.
A polysemic system: when the meaning of the individual signs are “deduced from consideration of the collection of signs” (pg.2)
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Stages in creating graphic diagrams (p.192)
- Order first into diagram network or map
- No. of neccessary visual variables; on tow three or more than three.
- Order the components: highlight, group or sequence
- (diagrams only) define length of components
- (networks and maps only) types of representation: point, line, area
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Types of graph
Diagrams (p.193)
- “the graphic is a diagram when the correspondances with the plane can be established among all the elements of one component and all the elements of another component.” (p.193)
- Unity: diagrams including 2 or 3 components can be constructed as a single image.
Networks (p.269)
- “when correspondences on a plane can be established among all the elements of the same component” (p.269)
- In a network, the plotting of the points on a plane has no meaning. The arrangement which produces the minimum number of intersections, therefore moving the visual easier to read, can be found by moving these points.
- Lines, points, size and shape have no meaning “their presence merely signifies presence of an element or of a correspondence between two elements” (p.269)
- A network can only be perceived as a single image when 2 components are involved.
Maps (p. 285)
- ” a graphic is a geographic “map” when the elements of a geographic component are arranged on a plane in the manner of their observed geographic order on the surface of the earth” (p.285)
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Image theory (p.139)
Efficiency
“the difference between an efficient construction and an inefficient one is extremely clear and can involve a considerable difference in perception time” (p.139)
Zipf’s notion of “mental cost” - research further
Stages in the reading process (p.140)
- External Identification: pre-required knowledge and identification of words shapes and colours
- Internal identification: viewer must recognise what visual components resemble what aspect.
- Perception of pertinent (new) correspondences: after identification of aspects, viewr then starts to take in data. Viewers form sub-consciously or consciously, a question which helps them to process the data.
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Retinal Variables (p.60)
“Experimental psychology defines depth perception as the result of multiple factors” (p.60)
- Binocular vision: within a limit of several metres.
- Apparent movement of objects: when the observer moves
- a decrease in the size of a known object
- a decreaes in the values of known contrast
- a reduction in the known texture of an object
- a decrease in the saturation of the colours of known objects
- deformations of orientation and shape (perspective)
Bertin, J. (2011). Semiology of graphics: diagrams, networks, maps. Redlands; Esri Press.
