Do you put social media data on a map? Location is a handy dimension for slicing, dicing, and visualizing your data. The question is, which location are you visualizing? Even a single tweet—in under 140 characters—can have four different locations.
I've taken a real interest in applying geospatial analysis to social media over the past year. It's been especially appropriate in emergency management and some other discussions with government types. Mostly, though, it's just another lens to apply to social media data, another way to find some value in the data we have now.
So, you want to put social media activity on a map. It's worth thinking about what that location really represents. One little statement can have four distinct locations, depending on how you look at it:
- Location of the service/server
Internet-based communications happen in this virtual space where physical location is largely irrelevant, but everything runs on a computer somewhere—even in the cloud.
You could even separate this one into two (or more) locations—the locations of the server and of the company that owns it—but for most of us, these are the least relevant locations. A few specialists need to know the physical or logical location of a server, but for the rest of us, there's nothing to see here.
- Location of the account
Look at an account on Twitter, Facebook, or other social network. Most of them have a place for users to provide their location. Its accuracy depends on the account owner, which is why you see so many Twitter accounts located in "Earth" or something similarly uninformative. During the pro-democracy protests in Iran, a lot of people set their Twitter locations to Tehran in sympathy with the protesters.
At its most useful, the location associated with an account tells you a default location for a user—home base.
- Location of the post
Social and mobile are increasingly two aspects of the same technology-adoption trend, as more people take their social media through mobile devices. With geolocation tagging and location-based services, they're sharing their immediate location: "I am here, now." This is the location you're most likely to see represented on a map.
- Location of the described event
This last location won't be encoded in an API, because it's found in the content people share. When they talk about events in the real world, they mention places, possibly indirectly. You'll need a text analytics tool that recognizes locations to extract those. When they post pictures, the photos may include location metadata from the camera.
- Let's say that I tweet about an event in Egypt (4) during a break at a conference in Washington (3). My account location (2) is in North Carolina. How does that compare with a geotagged photo (4) of the same event sent from Cairo (3) by an account that says it's located in Cairo (2)?
- It's another stormy day in the middle of America, and someone posts a picture of a damaged building (4) on Facebook. The account location (2) and post location (3) are nearly the same, and they're in the projected path of a tornado, based on National Weather Service radar data. Do you believe that a tornado hit the building?
Illustration: Map of a Twitter status object by Raffi Krikorian.