Visuale

Parallel Sets is a nice interactive tool presented at IEEE InfoVis 2005. It permits to visualize categorical data, i.e., data with no inerent ordering, with parallel coordinates.

The usual problem with this kind of data is that there is no natural mapping between values and positions on the axes, and then that parallel coordinates do not convey properly the amount of data falling in each category. Parallel Sets nicely resolve the problem using bands in place of simple lines, whose width is proportional to the frequency of items.

Also, a very interesting feature of the tool is that the user can compute new dimensions from existing ones on the fly and directly manipulate them in the visual space. It also has interesting drag and drop features and animation.

See more: webpage | infovis paper | video

Nice quote about the unfamiliarity of cartograms here:

Their main disadvantage is that they are unfamiliar, but we do not learn from familiarity

Here is a nice one depicting US elections:

What is a cartogram? In the author's words:

The basic idea is to distort a map by resizing its regions according to a statistical parameter, but in a way that keeps the map recognizable.

More info here.

Intelligent Icons use visualization and mining techniques to convey information about the content of files by means of small informative icons. Icons are built in a way that files with similar content share similar visual appearance and positioning, thus enabling comparison and grouping.

There are several interesting features in intelligent icons:

• Different color scales or layouts can be used to accommodate and distinguish between different file types, so that they don't get mixed up.
  
• The icons can be used at different resolutions so that they can scale to any default icon size provided by the operating system.
  
• A generic model is devised to permit the comparison of new file formats (through the development of novel plug-ins). The examples in the paper provide mechanisms for: dna data, time-series, pdf files, games.
  

The thing I like the most of this work, however, is the original approach and the paradigm shift from typical infovis tasks and scenarios. And this seems to be a specific purpose of the paper! In the authors' words:

The vast majority of visualization tools introduced so far are specialized pieces of software that are explicitly run on a particular dataset at a particular time for a particular purpose. In this work we introduce a novel framework for allowing visualization to take place in the background of normal day to day operation of any GUI based operation system such as MS Windows, OS X or Linux. By allowing visualization to occur in the background of quotidian computer activity (i.e. finding, moving, deleting, copying files etc) we allow a greater possibility of unexpected and serendipitous discoveries.

I like the idea of escaping the traditional infovis scenario: "get some data + give it a shape + provide interaction + let's go hunting for new knowledge!". I am sure the type of tasks that can be enabled by infovis and the different scenarios that can be covered go far beyond traditional data exploration (even if I think there is yet a lot to do in the traditional case), and this is a very good example.

For more information see the paper:

Intelligent Icons: Integrating Lite-Weight Data Mining and Visualization into GUI Operating Systems. E Keogh, L Wei, X Xi, S Lonardi, J Shieh, S Sirowy - ICDM 2006.

For some background info see also:

VisualIDs: automatic distinctive icons for desktop interfaces. JP Lewis, R Rosenholtz, N Fong, U Neumann - ACM Transactions on Graphics (TOG), 2004.

I've already touched the topic of visualizations able to expose human dynamics in a recent post about the F-shaped pattern of web reading behavior.

Here is TimeLine, a new and different example. TimeLine captures video streams an visualizes them in a way that it is possible to review your past minutes, hours, days, or weeks and detect behavioral patterns.

In the GroupLab @ University of Calgary's words, where it was conceived:

TimeLine was originally conceived to work as part of a media space, where people would use it to reveal their collaborator's events and activities over time, ostensibly to gauge their availability. It may also be useful for surveillance, for monitoring, and as an interactive art installation.

The technique is inspired by slit-scan photography a way to achieve blurriness or deformity exposing the film to only small fragments of the scene, with long exposures and panning. Video slicing extracts only a scan line from the video at a constant rate and add it to a queue of frames, as illustrated here below:

[source Nunes, M., Greenberg, S., Carpendale, S. and Gutwin, C. (2007) What Did I Miss? Visualizing the Past through Video Traces. Report 2007-855-07, Dept. Computer Science, University of Calgary, Calgary, Alberta, Canada. March. 21 pages.]

Frames at different intervals are used in the minute, hour, day, week view, selecting the video slices carrying more information.

What is really interesting, in my opinion, is the set of interactive techniques provided with the tool. They permit to effectively explore the past and detect interesting behavior. The main techniques are:

• Move slit position: the user can change the position of the video from which the slice is taken. Moving the slice in the real-time video window, it is possible to focus on alternative positions and all the views get instantly updated.
• Scrubbing: dragging the mouse over a video, it is possible to replay the scans at high rates back and forth, thus allowing for the detection and analysis of certain patterns (e.g., a person entering the room).
• Details of the past: selecting areas in the coarser views, it is possible to load past slices and review them at a higher resolution.

All these techniques are really hard to explain with words. I would also say that the entire system is hard to describe without seeing it in action. I highly suggest you to watch the video to understand how effective it can be. In fact, it is so effective that it raises serious privacy concerns, as deeply discussed by the authors.

Once again I think this is the kind of "experimental" visualization that can really open new perspectives. It is completely different from the standard data-feature mapping scheme of information visualization but still, I would say, it is a very good example of visualization. Information is continuously flowing in the system, and the visual abstraction is based on capturing pictures ... quite far from the more traditional "load a static dataset and explore" mindset of infovis.

Related Works:

	A library of slitscans can be found at Informal Catalogue of Slit-Scan Video Artworks as well as exploring the Flickr's tag "slitscan"
	Lastclock
	Artifacts of the presence era