plot types

[michaellevy]

Add breakdown of 1 vs. 2 vs. 3+ variable plots, with continuous and categorical variables. Make a table that they can see with a suggested first plot for each and the corresponding mappings and geom. I think this goes after introducing ggplot and geoms with scatterplots.

[michaellevy]

More ggplot reflections from HBS debrief:

• Order at top is weird: install and library
• Need mini-break in middle of lesson (as work is good but tough) and mini-review after break to give people a mental breather and help them assimilate materials
• More structure on types of graphs and when to use them
• Exercises were a little repetitious
• ?More exciting data sets to analyze. Or have them make gapminder data larger with addition of new columns?