Designers fuss over little details and so should you
Graphical forms impose assumptions on the data

To map or not to map

The New York Times shows the following set of maps to illustrate State policies relating to illegal immigrants. (link to article)



This is a great classroom exercise. The question is: to map or not to map. What are other possible displays and how do they compare?



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Spatial works fairly well, but I would try alternatives and compare. I find it difficult to decide until you've seen it in real life.

I would try states as rows with columns for each of the 4 outcomes then use the same colour scheme. Ordering of columns may not matter but trying the ones with most yellow first may work best. Then order states by either alphabetical or by difference in number of orange and green outcomes, which is probably better. Would be interesting to see how this was done in R.

Adam Schwartz

It seems to me, that map or no map isn't so much the issue as is how I'd expect the state to have acted given what I know about the state's liberal/conservative bent. The response to exective action map, being mostly filled in, looks a great deal like a map of red states/blue states would look.

Knowing the expectation of behavior, it makes TX, NE, and KS stand out on the "offers in-state tuition" chart. So, I think I'd like to see a display mechanism which adjusts for the delta. Does this tell us anything about motivation - states that don't hold the child accountable for the parent's actions, perhaps??? Pure speculation on my part.

I suspect the other option has to do with size of population impacted. A harsh policy in a populous state (having little to do with landmass) has more potential negative impacts than in a less populous state.

Either way, the map itself seems like a geography lesson.

Chris Pudney

Not a direct answer but by coincidence the NYT published these "maps" visualizing gay marriage state-by-state:

I particularly like this treatment as it removes the distortion arising from states of different sizes while retaining a measure of geographical coherence.

Whether it's appropriate in the case of the illegal immigration example is another matter.


can anyone recommend a free tool to create data maps? aka similar to excel power maps but for those who are on excel 2007?


Thanks for the suggestions, and keep them coming. The reason this is a nice exercise is that there are arguments for both. In addition, there are some creative ways and like Ken said, you really can't compare unless you have sketched alternatives.
Chris: that's a nice one, thanks for the link.
Ahmed: are you specifically wanting to do this within Excel?


"can anyone recommend a free tool to create data maps? aka similar to excel power maps but for those who are on excel 2007?"

Try Tableau Public

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