Whenever discussing the relation between HCI and visualization in general or when presenting research results in these areas, questions arise about the differences between these research fields. These questions, at the same time, provoke awareness of fundamentally different views on the "science" of computer science – is this a natural science, an applied science, or applied humanities? Being active in different faculties in different universities and companies, for most of us this is one of the major daily fights in coffee rooms, lecture halls, as well as in board meetings.

One of the major issues is that it is not easy to precisely define the terms visualization and HCI and that there are many interpretations of these two fields that appear to be distinct.
ACM SIGCHI tries to give people a working definition for HCI: “Human-computer interaction is a discipline concerned with the design, evaluation and implementation of interactive computing systems for human use and with the study of major phenomena surrounding them.“ [1] However, at the same time the applicability of this definition is significantly limited by adding that it “at least permits us to get down to the practical work of deciding what is to be taught“.
Similar imprecise descriptions can be found for visualization. One possibility is the classical definition given by ACM SIGGRAPH: “visualization is […] the formation of mental visual images, the act or process of interpreting in visual terms or of putting into visual form” [2], though the visualization subcommittee of the SIGGRAPH Education Committee in 1997 provided an alternative: “a computer generated image or collection of images, possibly ordered, using a computer representation of data as its primary source and a human as its primary target” [3]. Foley [4], in 1994, states “A useful definition of visualization might be the binding (or mapping) of data to a representation that can be perceived. The types of binding could be visual, auditory, tactile, etc. or a combination of these”. Kosara [5] tries to better conceptualize the term visualization by defining some criteria forming a minimal set of requirements for any visualization: “visualization is based on (non-visual) data, produces an image, and results in a readable and recognizable output”. Finally, some definitions are approaching the concept from the point of view of computing: “Visualization is a method of computing. It transforms the symbolic into the geometric, enabling researchers to observe their simulations and computations. Visualization offers a method for seeing the unseen. It enriches the process of scientific discovery and fosters profound and unexpected insights. In many fields it is already revolutionizing the way scientists do science” [6].

As already mentioned, questioning similarities, differences, and correlations of HCI and Visualization form an important part of our daily work life. In order to better (or at all) answer these questions, in our workshop we want to discuss topics like:

• What is HCI? What is Visualization? What is a working description that is practical highlighting the special features of each of the fields?
• Are there other disciplines involved in this struggle (e.g., Visual Analytics)?
• How can we take advantage of the two fields and how can we find ways for people with different inclinations to collaborate and take advantage of the strengths of each other?
• What are the similarities of the disciplines? What are the major differences?
• Do we need to really split the domains? Or do we need to join them and provide a joint curriculum for studying and practicing them?
• Can we give definitions that are better applicable in real situations?
• Does one need to further research the ways to make people take advantage of both disciplines in designing interactive visual systems? In that case, what are the research agenda(s) and what are the Top 10 Research Challenges?

References

1. Hewett, Baecker, Card, Carey, Gasen, Mantei, Perlman, Strong, and Verplank: ACM SIGCHI Curricula for Human-Computer Interaction; Chapter 2: Human-Computer Interaction. Last updated in 2009.
2. ACM SIGGRAPH: Definitions and Rationale for Visualization. Last updated in 1999.
3. Domik G., 2008, Computer-generated Visualization 1. Introduction to Visualization. Retrieved March 14, 2011, from www.cs.uni-paderborn.de/fileadmin/Informatik/AG-Domik/VisCurriculum/pdf/introduction.pdf
4. Foley J. and Ribarsky B., Next-generation Data Visualization Tools, in Scientific Visualization, 1994, Advances and Challenges, Ed: L. Rosenblum, R.A. Earnshaw, J. Encarnacao, H. Hagen, A. Kaufman, S. Klimenko, G. Nielson, F. Post, D. Thalmann , Academic Press
5. Kosara: Visualization Criticism – The Missing Link Between Information Visualization and Art. Proceedings of the 11th International Conference Information Visualization, 2007.
6. McCormick, B.H., T.A. DeFanti, M.D. Brown (ed), Visualization in Scientific Computing, Computer Graphics Vol. 21, No. 6, November 1987