Sunday, August 18, 2013

How recent is recent?

Over the past decade, maps have become a common addition to news media websites.  As a GIS geek, I always appreciate a well-executed map.  Maps help me visualize data that would be, well, flat in a mere table.  I especially like interactive maps, the kind that allow you to zoom in and out, change the view, manipulate the data, drill into more detail and so forth.

For several years now, the Omaha World Herald has been using Google Maps, and more recently Leaflet, to produce several kinds of maps (and some other interesting data) on their website. Among these is a map of homicides.  This is what the map looked like Saturday morning.

The online version is interactive: you can click on an icon and get some details, including a link to a relevant World Herald story. The map is titled "2013 Omaha homicides," but there is no indication of its currency. One might assume that it presents the data as of the date of publication, but that is not the case. There is (understandably) a lag of several days before a new murder hits the map. The tabular data is presented below the map, so you can scroll down to see the most recent mapped murder and then add on any more that have occurred in the interim. The most recent murder on the map was on August 4th, so I added five more that are reported in the news since August 4th, but not yet mapped.

The Lincoln Journal Star also publishes many interesting maps, including a map of murders which appears in the sidebar of the "911 News" page.  This is what it looked like Saturday morning.

The map is labeled "Recent Lincoln Murders." There is no description of the date range, other than the term "recent." Like the World Herald map, there is also no description of the ending date, leading one to wonder, just how current is the map? You can click the icons on the LJS map and get the details and links, just like to OWH map, but unlike the Omaha map, you can't scroll down to take a look at the data presented in a table. So if you want to know the date range, you'd really have to click on each individual icon and keep track of the dates on a scratch pad.

I did just that, and determined that "recent" in the title of this map apparently means within the previous 12 full years, because none of the 2013 murders appears on the map, and the earliest murders mapped were in 2001. To be fair, if you took the link to "Large map," the title on that page would indicate "Lincoln murders, 2001- present." This is still not quite accurate, since the 2013 murders do not appear) but at least an indication that the map of "recent murders" starts in 2001. That's the same year that Apple introduced that fancy new-fangled device known as the iPod, which soon made your Walkman obsolete.

If you're a data hound interested in such things, it's hard to beat the Lincoln Police Department's online tool for generating your own statistical tables.

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