Visualization

Draft

Definition

The idea is to use a graphical representation to represent an information space, e.g. a complex concept, a WebSite or parts of the Web as a whole, user activities ....

DSchneider doesn't know if we should split this up like for example the Wikipedia:Visualization article (and add multimedia animations which are not necessarily the same as what they call Wikipedia: Knowledge visualization).

Types of visualizations

Lloyd Rieber (2002) categorizes visualizations according to their physical characteristics.

• representational - resemble the object represented ranging from realistic (photographs) to simplified lines and shapes.

• analogical - using a representation of an object with similar qualities to those of the object under study to highlight particular characteristics and phenomena (e.g. billard balls to introduce the concepts of momentum and kinetics of atomic particles).

• arbitrary - graphics that do resemble the concepts in question but reveal information through their spatial characteristics and the relationships between different elements of the graphics (e.g. charts, graphs, concept maps, outlines).

Visualization in education

Here is (quick) some brainstorming regarding different areas:

• To organize complex information spaces (a good example is the Java visualization of this wiki). An other is tools like Nestor that maps out search results.

• To map out concepts and relations with some kind of graph semantic map [e.g. Wikipedia: Mind map Wikipedia: Concept Map

• To display social webs and show what people do

• To display complex (subject) data, i.e. students use a real tool

• To organize & moderate group or class discussion (e.g. [1] [2] [3] [4] [5]) writable tables or other devices

Learners, can either use or build visualizations (or both of course). We shall put some emphasis on building of course ...

Technology

Graphic model

• Various concept maps (e.g. mind maps)
• Topic maps
• Tree maps and pyramid maps
• Fractal maps
• Dynamic diagrams (e.g. [6])
• Flowcharts
• Venn diagrams
• Tree diagrams
• Network trees
• Fishbone maps
• Cycles
• Spider webs

Representation languages

See also formalisms used to represent semantic networks, ontologies, etc.

• The DOT Language
  • dot guide
  • WikiSchool:Graphviz (Tutorial in German)

Viewers

The principle is that such software can render graphs using some kind of formal representation language.

GraphiViz Viewers:

• ZGRViewer. GraphViz/DOT Viewer
• iDot - Incremental Dot Viewer

Tools

(really not complete, includes both )

• Graphviz (a very popular and free visualization program for which many add-ons exist, e.g. viewers)
• Graphviz (is an open source graph visualization software. It has several main graph layout programs)
  • Download of GraphViz software (source and Win/Linux binaries). Note: For Ubuntu I found it through package manager to install (there are quite a lot of dependencies). For solaris, you can download a binary from sunfreeware.com plus these: cairo-1.4.10, freetype-2.3.1, glib-2.14.1, graphviz-2.16.1, pango-1.18.2, xrender-0.8.3,expat-2.0.1.
  • Graphviz - Graph Visualization Software (a longer list of interfaces, bindings, generators, scripts, etc.). Usually also needs graphviz software and the other way round. I.e. after installing Graphviz, you likely want to install a viewer or generator.
  • GraphViz Widget for Mediawikis (alpha status in Feb 2008).
  • Extension:Graphical Category Browser for MediaWiki (>1.7x). This may be outdated.
  • http://www.mediawiki.org/wiki/Extension:GraphViz Extension:GraphViz] MediaWiki extension (Tested in this wiki. Worked with Mediawiki version 1.11, Graphviz 2.16.1 on Solaris 10 - DKS/2008)
  • Graphviz (Wikipedia)
  • An Introduction to GraphWiz, September 10th, 2004 by Mihalis Tsoukalos, Linux Journal

• Treemaps for space-constrained visualization of hierarchies. by Ben Shneiderman et al. (various software, some free)

• Tulip, created by David AUBER, is a contribution of the area of information visualization, “InfoViz”. Even if the Tulip framework allows the visualization, the drawing and the edition of small graphs, all the parts of the framework have been built in order to be able to visualize graphs having more than 1.000.000 elements

• Demolist from Laboratory for Information Visualization and Evaluation

Programming languages

• Processing is a popular open source programming language and environment for people who want to program images, animation, and interactions. It is used by students, artists, designers, researchers, and hobbyists for learning, prototyping, and production. It is created to teach fundamentals of computer programming within a visual context and to serve as a software sketchbook and professional production tool.

In addition to special purpose languages like processing, any programming language with sufficient graphics can do, e.g.

• JavaScript, in combination with various formats like SVG, X3D.

• Actionscript 3, i.e. ECMAScript with Flash bindings.

Links

Overviews

• Knowledge Maps of Researchers and Methods in the Visualization Field.
  • Check the "periodic table at the bottom of the page": Open the link and move your mouse over the cells. A really spectacular summary of different methods !
  • There is also an associated paper
• Visual Mapping A short module with pictures of different maps (part of a free visual thinking school on-line course).

Indexes

• some links collected for a course

On line examples

• Atlas of Cyberspaces
• Chris Harrison Visualization Projects (e.g. Wikipedia, Bible)
• Sense.us collaborative visualization system

References

• Heer Jeffrey; Fernanda B. Viégas, Martin Wattenberg, (2007). Voyagers and Voyeurs: Supporting Asynchronous Collaborative Information Visualization, ACM Human Factors in Computing Systems (CHI), Abstract/PDF/Video.

• Rieber, L. (2002) Supporting discovery-based learning with simulations. International Workshop on Dynamic Visualizations and Learning. Online-Proceedings, Knowledge Media Research Center (KMRC), Tübingen, Germany. pdf

• Ralph Lengler & Martin J. Eppler, Towards A Periodic Table of Visualization Methods for Management, Institute of Corporate Communication, University of Lugano, Switzerland, PDF"]