[cyrillevincey]

Indeed it's a 101. Thanks for your comments. The only one I would really disagree with is "always represent more than one data series". That's really tough to represent multiple series on one single chart and manage to keep it immediatly readable.

[couchand]

Certainly a chart should be readable, but I think it's okay to ask for a few moments of careful study. I'm much more interested in a chart that provides some context or basis for comparison, if not with several series than with small multiples or a representation of the general distribution.