[R] perception of graphical data

Yeh, Richard C richard.c.yeh at bankofamerica.com
Fri Aug 24 19:30:56 CEST 2007


I apologize that this is off-topic.  I am seeking information on
perception of graphical data, in an effort to improve the plots I
produce.  Would anyone point me to literature reviews in this area?  (Or
keywords to try on google?)  Is this located somewhere near cognitive
science, psychology, human factors research?

For example, some specific questions I have are:

I recall as a child when I first saw a map where the areas of the
containers (geographical states) were drawn as rectangles, proportional
to a quantity other than land area.  Does anyone know of an algorithm
for drawing such maps?  Would anyone know of a journal or reference
where I can find studies on whether subjects reading these maps can
accurately assess the meaning of the different areas, as [some of us]
can assess different heights on a bar graph?  (What about areas in bar
graphs with non-uniform widths?)

Scatter plots of microarray data often attempt to represent thousands or
tens of thousands of points, but all I read from them are density and
distribution --- the gene names cannot be shown.  At what point, would a
sunflowerplot-like display or a smooth gradient be better?  When two
data points drawn as 50% gray disks are small and tangent, are they
perceptually equivalent to a single, 100% black disk?  Or a 50% gray
disk with twice the area?  What problems are known about plotting with
disks --- do viewers use the area or the diameter (or neither) to gauge

As you can tell, I'm a non-expert, mixing issues of data interpretation,
visual perception, graphic representation.  Previously, I didn't have
the flexibility of R's graphics, so I didn't need to think so much.
I've read some of Edward S. Tufte's books, but found them more
qualitative than quantitative.



212-933-3305 / richard.c.yeh at bankofamerica.com

More information about the R-help mailing list