Ma*n, thanks for pointing out the talk slides(?) and N*ck for writing them.
Just looked a bit into them and found some very interesting graphs I didn't see before.
"Table plots" seem to be a good alternative for colouring.
Nick Cox wrote:
Colour-coding cells, however, covers at least two kinds of idea:
1. Qualitative coding: Look! This cell contains a very high value, [...]
2. Quantitative coding: Look! In addition to showing you the values, I am also using a series of colour shades. [...]
Indeed, color shading like in the given example may not enhance the readability of a table. I also found that the excel algorithm (which I don't know) leads to strange results sometimes.
I use quantitative coding only with few colour categories (beside: I mainly use greys, yellow to brown, purples or - if applicable to the data - traffic lights: green, yellow and red).
One example of the last: 24 regional units deliver data to one dataset I maintain. Last year we had a major shift in data documentation causing a lot of problems inside the regional agencies. After receiving the data I calculated the proportion of missing values for each var by regional unit (>1000 cells) with Stata. I copied the resulting "missing data matrix" to Excel and applied colours (<5%: green; 5- <20%: yellow, 20%+: red). During the process of data preparation I updated this table on a daily basis and it proved to be a valuable tool.
Thanks
St*n
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