The Table Lens: Merging Graphical and Symbolic Representations in an Interactive Focus + Context Visualization for Tabular Information R. Rao and S. K. Card Present by Tao Zhan

Focus + Context (Fisheye) Motivation –a view of the whole data available, while pursuing detail analysis of a part of it –Problems in overview + detail: visual search and working memory consequences degrade performance –user’s interest in detail fall away from the object of attention in a systematic way

Focus + Context (Continue) Basic Idea –detail information and relevant context overview are combined within a single (dynamic) display –DOI: a metric that is the sum of a priori measure of importance and distance from the point of interest –method of reduction of information for the peripheral, contextual area

Focus + Context (Continue) Key factors –zoom factor –focus/context space ratio –whether the zoom factor is a step function or continuous function –whether the fisheye effect is obtained by geometrical distortion, elision, or semantic scaling

Table Lens Motivated by the particular nature of tables Distort table without bending any rows or columns Distortion in each of the two dimensions is independent from the other HG 4 5 6

Distortion Function Framework Each dimension has a block pulse DOI Mapping from uniformly distributed cell to physical location Multiple focal areas and Multiple focal levels are possible

Interactive Manipulation of Focus Zoom Adjust Slide Combined

Graphical Mapping Scheme Value Value Type Region Type Cell Size User Choice Spotlighting

Examples & Conclusion Examples Strength and Advantage –supports effective interaction with much larger tables than conventional one (68,400 V.S. 660) –graphical representations make it easy to view patterns for cell value –Suitable for large dimensional data and reveal correlation and patterns between them

Critique Zoom Factor may be too big Nominal variables with large domain are hard to present graphically Search is not trivial in Table Lens

Favorite Sentence Always take flight to where there is a free view over the whole single great problem, even if this view is still not a clear one.