Information Visualization is branch of Human-Computer Interaction field with origins in late '80. It exploits graphics to help people comprehend and interpret data. If helps in forming mental models of the data and obtain a better understanding of specific features of the data.
Information Visualisation is a relatively new discipline concerned with the creation of visual artefacts aimed at amplifying cognition. A number of new definitions have been produced to define the scope of this discipline. The Information Visualisation Research Group at the Institute for Software Research at University of California, Irvine cite on its Web pages:
Information visualization focuses on the development and empirical analysis of methods for presenting abstract information in visual form. The visual display of information allows people to become more easily aware of essential facts, to quickly see regularities and outliers in data, and therefore to develop a deeper understanding of data. Interactive visualization additionally takes advantage of people's ability to also identify interesting facts when the visual display changes, and allows them to manipulate the visualization or the underlying data to explore such changes (http://www.isr.uci.edu/research-visualization.html, visited June 2003)
Similarly, the User Interface Research Group Web-site of the Palo Alto Research Centre (PARCXEROX) defines that:
Information Visualization is the use of computer-supported interactive visual representations of abstract data to amplify cognition. Whereas scientific visualization usually starts with a natural physical representation, Information Visualization applies visual processing to abstract information. This area arises because of trends in technology and information scale. Technically, there has been great progress in high-performance, affordable computer graphics. At the same time, there has been a rapid expansion in on-line information, creating a need for computer-aid in finding and understanding them. Information Visualization is a form of external cognition, using resources in the world outside the mind to amplify what the mind can do. (http://www2.parc.com/istl/projects/uir/projects/ii.html, visited June 2003)
The above definition is appropriate nowadays with the computers being a constant part of our life, but as Spence (2001) and Hearst (2003) pointed out the role of computers is merely of a mean that facilitates visualisations. Hearst (2003) summarises that IV is:
The depiction of information using spatial or graphical representations, to facilitate comparison, pattern recognition, change detection, and other cognitive skills by making use of the visual system.
"Usability First", a web site that provides information and resources related to usability in website and software design, provide this definition:
the study of how to effectively present information visually. Much of the work in this field focuses on creating innovative graphical displays for complicated datasets, such as census results, scientific data, and databases. An example problem would be deciding how to display the pages on a website or the files on a hard disk. Visualization techniques include selective hiding of data, layering data, taking advantage of 3-dimensional space, using scaling techniques to provide more space for more important information (e.g. fisheye views), and taking advantage of psychological principles of layout, such as proximity, alignment, and shared visual properties (e.g. color). (http://www.usabilityfirst.com/glossary/main.cgi?function=display_term&term_id=5 visited March 2005)
IV has a long history having its origin from the historical works of J. H. Lambert [1728-1777] and William Playfair [1759-1823] who were the first to introduce graphics, in contrast with the tabular presentation of data and are considered the inventors of the modern graphics design (Tufte, 1983). Starting with Playfair, data were represented with methods of plotting. Other important contributions were made more recently by Jacques Bertin and Edward Tufte. Bertin, a French cartographer, was the first who tried to define, in 1967, a theory of IV by the identi cation of the basic elements of diagrams and described a framework for graphics design (Bertin, 1983). In 1983 Tufte published his theory of data graphics focused on the maximisation of the density of useful information in graphics (Tufte, 1983). Both Bertin and Tufte's theories have in uenced the current development of IV.
See Important authors for a description of some authors that originated this discipline.