For decades, a core tenet of visualization theory has been to break down the structure of visual encodings into marks and channels: geometric marks that represent data items, whose visual appearance can be controlled by visual channels such as position, color, shape, and size. Very extensive empirical work has been carried out to characterize the expressiveness and effectiveness of these visual channels and their relative rankings, resulting in sophisticated models for how to use them. However, the situation with marks is much less well studied; researchers have continued to simply divide them into the mathematically-inspired categories of point, line, area, and volume, following proposals by Jacques Bertin dating back to the 1960s. I will present and discuss many scenarios where this conventional model falls short, in some cases even for well known chart types. I will introduce ideas about alternative models that may provide better descriptive and generative power, to resolve ambiguities and help visualization designers reason about visual encoding possibilities.
Tamara Munzner is a Professor at the University of British Columbia Department of Computer Science, and holds a 2000 PhD from Stanford. She has been active in visualization research since 1991 and has published over ninety papers and chapters. She has been papers chair for IEEE InfoVis, EuroVis, and VIS, on the steering committees for InfoVis and BioVis, and the chair of the VIS Executive Committee. Her book Visualization Analysis and Design is widely used to teach visualization world-wide, and she is the co-editor of the A K Peters Visualization book series at CRC/Routledge. She received the IEEE VGTC Visualization Technical Achievement Award, multiple Test of Time Awards from InfoVis, and is an IEEE Fellow.
This talk will be streamed over Zoom: https://mit.zoom.us/j/99804195917.