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
4
5
6
G
H
G4
H4
G5
H5
G6
H6
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
DOI
X
Focal
Area
J
Interactive Manipulation of Focus
•
•
•
•
DOI
Zoom
Adjust
Slide
Combined
DOI
X
X
J
J
Zoom
Adjust
DOI
X
J
Slide
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.