3.31 Perception: Acceptability principles
“Understanding Charts and Graphs” (Kosslyn 1989): Contains lessons on how to think about your audience/perception/decoding17
- ‘acceptability principles’ are derived from facts about human visual information processing and from an analysis of the nature of symbols
- Visual information processing: Perceptual image (1) → Short-term memory (2) → Long-term memory (3) (Kosslyn 1989, 190–91)
(1), (2) and (3) are linked to the audience you have (this includes yourself!)
Kosslyn (1989) goes into more detail, however, for us the here mentioned concepts are useful enough
Q: Knowing these concepts what questions would you ask yourself when you see a graph and evaluate it?
- e.g., Is the viewer able to discriminate the different categories in the graph?
References
Kosslyn, Stephen M. 1989. “Understanding Charts and Graphs.” Appl. Cogn. Psychol. 3 (3): 185–225.
“This article develops a way of analysing the information in charts and graphs that reveals the design flaws in the display” (Kosslyn 1989).↩
Adequate discriminability: Variations in marks must be great enough to be easily noted. This principle has two aspects (Kosslyn 1989, 195); Perceptual distortion: Marks should be used that are perceived veridically (Kosslyn 1989, 195); Priority: Some aspects of a stimulus are given priority over others ; we pay attention first to abrupt changes of any sort (e.g. heavier marks, brighter colours) (Kosslyn 1989, 191). Partly because only a limited amount of information can be held in short-term memory at once, some marks will be given priority over others. The information conveyed by these marks should be central to the display’s message (Kosslyn 1989, 196); Organized: Stimuli are organized into coherent groups and units by the time we become aware of them. Much of this organization is ‘automatic’ , not under voluntary control, and is determined by reasonably well-understood properties of stimuli (e.g. proximity of elements). The grouping imposed by these automatic_processes must be respected if a chart or graph is to be seen the way a designer intends (Kosslyn 1989, 191).↩
Kosslyn (1989) also discusses Goodman (1976)’s theory of symbols but to me it seems less useful to the applied data scientists.↩