Sometimes when I tell people that I make maps for a living, this kind of perplexed look passes over their faces. They seem to be wondering: what can possibly be left to map? They are most likely thinking about road or topographic maps, which seek to depict physical features on the earth's surface as accurately as possible. And aside from updating and quality improvement, there isn't much "new" cartography to be done.
But the maps I make are thematic, meant to highlight a particular idea or topic. Because data frequently change or are created, there's always something new to be mapped. In many cases, the data have been around for a while, but no one thought to map it. Or if they mapped it, they didn't do a very good job of it. By 'good,' I mean the map does not clearly communicate what it is meant to communicate. It doesn't necessarily have to be attractive, though there is no particular reason why it shouldn't be, as long as it is comprehensible, and accurate. There are numerous design elements that go into creating a good map, text placement, layout, symbology, etc, and those are easily learned about with some additional reading (I highly recommend the British Cartographic Society's short and sweet Cartography: an introduction).
like to do is focus on a specific example.
Earlier this week our governor announced his budget plan for the coming
year, which includes a 30% decrease in funding for state-related schools like
Penn State. Our student body of 96,519
is distributed across 24 campuses and cyberspace. I was curious about what our enrollment numbers
would look like on a map. In digging
through the online Fact Book for 2011's enrollment, I came across a Total
Enroll by Location page that included a map and a table.
The map really just serves as a reference, and doesn't add any benefit to understanding the data. And even then, it doesn't do a particularly good job. For example, there's no relationship between campus locations/enrollment and the mountains, so why show them (and in wrong places, no less)? Ditto for the rivers; furthermore, there's an odd break in the middle of the Susquehanna that is inaccurate. Text placement is poor and crowded. The campus symbols would stand out better if they were outlined or were darker.
this is what a thematic map could do:
The topic at hand is emphasized by not showing extraneous features, such as mountains and rivers. Proportional symbols show the data in a glance. With enrollment numbers included on the map, the reader's eye doesn't need to track back and forth from table to map and back. The symbol is dark, stands out, and is tailored to the theme.
It may not win any awards, but by my count, this is a good map: it does what it needs to do. And that, I think, makes the difference.