Relevant notes taken from throughout Bertin’s book covering all areas of information visualisation.
"…graphics is one of the major "languages" applicable to information processing" (p.2)
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)
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
Types of graph
- "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.
- "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)
Image theory (p.139)
"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.
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.