Information Visualization: Perception for Design - Colin Ware (1999)

Key Quotes:

• 'As Hutchins (1995) so effectively pointed out, thinking is not something that goes on entirely, or even mostly, inside people's heads. Little intellectual work is accomplished with our eyes and ears closed. Most cognition is done as a kind of interaction with cognitive tools, pencils and paper, calculators, and increasingly, computer-based intellectual supports and information systems.' p.8
• 'Visualizations have a small but crucial and expanding role in cognitive systems.' p.8
• 'We acquire more information through vision than through all of the other senses combined. The 20 billion or so neurons of the brain devoted to analyzing visual information provide a pattern-finding mechanism that is a fundamental component in much of our cognitive activity.' p.8
• 'One of the greatest benefits of data visualization is the sheer quantity of information that can be rapidly interpreted if it is presented well.' p.8
• 'Visualization provides an ability to comprehend huge amounts of data. The important information from more than a million measurements is immediately available.' p.9

Visualization Stages:

• 'In general, algorithms are discussed only insofar as they are related to perception. The computer is treated, with some reservations, as a universal tool for producing interactive graphics. This means that once we figure out the best way to visualize data for a particular task, we assume that we can construct algorithms to create the appropriate images. The critical question is how best to transform the data into something that people can understand for optimal decision making.' p.11

Experimental Semiotics Based on Perception:

• 'about the science of visualization, as opposed to the craft or art of visualization.' p.11
• 'Some scholars argue that visualization is best understood as a kind of learned language and not as a science at all. In essence, their argument is that visualization is about diagrams and how they can convey meaning. Generally, diagrams are held to be made up of symbols, and symbols are based on social interaction. The meaning of a symbol is normally understood to be created by convention, which is established in the course of person-to-person communication. Diagrams are arbitrary and are effective in much the same way as the written words on this page are effective-we must learn the conventions of the language, and the better we learn them, the clearer that language will be.' p.11-12
• 'the debate can help us define where vision research can assist us in designing better visualizations, and where we would be wise to consult a graphic designer trained in an art college.' p.12

Semiotics of Graphics:

• 'some visual languages are easier to "read" than others. But why?' p.12
• Saussure -  'He defined a principle of arbitrariness as applying to the relationship between the symbol and the thing that is signified.' p.12
• 'truth is relative to its social context. Meaning in one culture may be nonsense in another. A trash can as a visual symbol for deletion is meaningful only to those who know how trash cans are used.' p.12
• Levi-Strauss, Barthes and Lacan - 'have developed the theory that all meaning is relative to the culture. Indeed, meaning is created by society.' p.14
• 'Languages are conventional means of communication in which the meanings of symbols are established through custom. Their point is that no one representation is "better" than another. All representations have value. All are meaningful to those who understand them and agree to their meanings.' p.14

Pictures as Sensory Languages:

• 'There has been a debate over the last century between those who claim that pictures are every bit as arbitrary as words and those who believe that there may be a measure of similarity between pictures and the things that they represent. This debate is crucial to the theory presented here; if even "realistic" pictures do not embody a sensory language, it will be impossible to make claims that certain diagrams and other visualizations are better designed perceptually.' p.14
• Nelson Goodman (1968) - '"Realistic representation, in brief, depends not upon imitation or illusion or information but upon inculcation. Almost any picture may represent almost anything; that is, given picture and object there is usually a system of representation-a plan of correlation under which the picture represents the object."' p.14
• 'the best approach to designing visual languages would be to establish graphical conventions early and stick to them.' p.14
• Kennedy (1974) - 'In the case of the reported puzzlement of people who are seeing pictures for the first time, Kennedy argues that these people are amazed by the technology rather than unable to interpret the picture. After all, a photograph is a remarkable artifact. What curious person would not turn it over to see if, perhaps, the reverse side contains some additional interesting information?' p.15 

Sensory versus Arbitrary Symbols:

• 'the word sensory is used to refer to symbols and aspects of visualizations that derive their expressive power from their ability to use the perceptual processing power of the brain without learning.' p.16
• 'The word arbitrary is used to define aspects of representation that must be learned' p.16
• 'Sensory representations are effective (or misleading) because they are well matched to the early stages of neural processing. They tend to be stable across individuals, cultures, and time. A cave drawing of a hunt still conveys much of its meaning across several millennia. Conversely, arbitrary conventions derive their power from culture and are therefore dependent on the particular cultural milieu of an individual.' p.16
• 'because we all have the same visual system, it is likely that we all see in the same way, at least as a first approximation. Hence, the same visual designs will be effective for all of us.' p.18
• 'This distinction between the sensory and social aspects of the symbols used in visualization also has practical consequences for research methodology. It is not worth expending a huge effort carrying out intricate and highly focused experiments to study something that is only this year's fashion. However, if we can develop generalizations that apply to large classes of visual representations, and for a long time, the effort is worthwhile.' p.18-19

Arbitrary Conventional Representations:

• 'Arbitrary codes have the following characteristics:
• Hard to learn
• Arbitrary codes are by definition socially constructed - 'In contrast, sensory codes cannot be forgotten. Sensory codes are hard-wired; forgetting them would be like learning not to see. Still, some arbitrary codes, such as written numbers, are overlearned to the extent that they will never be forgotten. We are stuck with them because the social upheaval involved in replacing them is too great.' p.22
• Embedded in culture and applications - 'The use of color codes to indicate meaning is highly culture-specific.' p.22
• 'Many graphical symbols are transient and tied to a local culture or application. Think of the graffiti of street culture, or the hundreds of new graphical icons that are being created on the Internet.' p.22
• 'We have many standardized visualization techniques that work well and are solidly embedded in work practices, and attempts to change them would be foolish. In many applications, good design is standardized design.' p.22
• 'Culturally embedded aspects of visualizations persist because they have become embedded in ways in which we think about problems.' p.22
• Formally powerful - 'the fact that something is expressed in a visual code does not mean that it is easy to understand.' p.23
• Capable of rapid change - 'Sensory codes are the products of the millions of years it has taken for our visual systems to evolve. Although the time frames for the evolution of arbitrary conventional representations are much shorter, they can still have lasted for thousands of years (e.g., the number system). But many more have had only a few decades of development. High-performance interactive computer graphics have greatly enhanced our capability to create new codes.' p.23

The Study of Arbitrary Conventional Symbols:

• 'For the visualization designer, training in art and design is at least as useful as training in perceptual psychology. For those who wish to do good design, the study of design by example is generally most appropriate. But the science of visualization can inform the process by providing a scientific basis for design rules, and it can suggest entirely new design ideas and methods for displaying data that have not been thought of before. Ultimately, our goal should be to create a new set of conventions for information visualization, based on sound perceptual principles.' p.23-24

A Model of Perceptual Processing - Stage 1: Parallel Processing to Extract Low-Level Properties of the Visual Scene:

• 'Visual information is first processed by large arrays of neurons in the eye and in the primary visual cortex at the back of the brain. Individual neurons are selectively tuned to certain kinds of information.' p.26
• 'If we want people to understand information quickly, we should present it in such a way that it could easily be detected by these large, fast computational systems in the brain.' p.27

Conclusion:

• 'New symbol systems are being developed constantly to meet the needs of a society increasingly dependent on data. Once developed, they may stay with us for a very long time, so we should try to get them right.' p.33
• 'If the best representation is simply the one we know best because it is embedded in our culture, then standardization is everything-there is no good representation, only widely shared conventions.' p.33