Economist’s Africa Twitter map provides some teachable insights

Ralph Straumann

Ralph is a world-citizen, a geoinformation specialist by profession, and interested in many topics. Here, he'll confine himself mostly to things geo-visual.

You may also like...

3 Responses

  1. Frank says:

    We’ve been collecting Tweets from the garden-hose sample and a keyword-based search of the streaming API for many months, and I can support the critique. In our case, we have roughly 1% of Tweets geocoded. We also looked into the various ways of using location (searching for placenames in the text, the user location, and any place info added by Twitter). We also found that user profile location is highly unreliable as a substitute. Furthermore, the whole geocoded issue is a terrible mess, because of the various ways a Tweet can be geocoded: Via GPS of the device, or via a user choice of a place and subsequent geocoding by Twitter. In both cases, the results can vary, because of user preferences and software design. For example, a Twitter app can present the user a selection of places to choose from, which does not have to be exhaustive. A user can set a level of detail for Twitter geocoding, e.g. neighborhood, city, country. Some apps put the device’s GPS coordinates in the user profile location info. Etc. Etc.

    • Ralph says:

      Thanks for your more detailed insights, Frank. So, from your words I take you actually declare Twitter’s location information pretty much devoid of any analysis value, as of now? Or would that be an exaggeration and there may be some use cases where Twitter location information is okay to rely on?

      • Frank says:

        I wouldn’t go that far. Simply because of the amount of info available and the richness of the metadata (about user accounts, interactions, etc.), Twitter location information has potentially high analysis value. But you need to be aware of the serious limitations, i.e. the sample of geocoded Tweets (and their authors) is likely not representative of the whole Twitterverse, using user profile location is not a good substitute for actual Tweet location, device GPS accuracy may be low, and you don’t always have the lineage (origin) of the geocoding (i.e. user choice, device, Twitter). The other option to increase geocoded Tweets is to geocode them yourself, by extracting toponyms from the content and look them up in a gazetteer. That’s what we’re doing. We have not yet examined the relation between our (simplistic) approach and the “official” Twitter or user device GPS geocoding. It’s on the agenda…

Please let us know your opinion: Reply here

%d bloggers like this: