graphics defaults
Can someone point me to a justification for the design decisions, which seem to be similar in lattice and ggplot2, of (1) gray backgrounds and (2) filled points? [I seem to remember seeing somewhere the opposite recommendation for points, i.e. that open points make it much easier to see if there are overlapping values -- and this would be a reason that pch=1 gives an open circle ...]
From a paper I'm working on:
This follows from the advice of
\citet{tufte:2006,tufte:1990,tufte:2001,tufte:1997} and
\citet{brewer:1994,carr:2002,carr:1994,carr:1999}. We can still see
the gridlines to aid in judgement of position \citep{cleveland:1993a},
but they have little visual impact and we can easily ``tune'' them
out. The grey background gives the plot a similar colour (in a
typographical sense) to the remainder of the text, ensuring that the
graphics fit in with the flow of a text without jumping out with a
bright white background. Finally, the grey background creates a
continuous field of colour which ensures that the plot is perceived as
a single visual entity.
I can dig out the exact references if you need them.
Hadley