Geotagging and sentiment analysis

I’ve been scouting out OpenCalais these last couple days as we think we may want to use their service as a jumping of point for some other products we’ve been thinking about developing. In case you’re unfamiliar with OpenCalais, they have a suite of tools and plugins that automatically generate rich metadata for your web content. Using a combination of natural language processing and machine learning, Calais analyzes your text and finds the entities (people, events, products, relationships) within it, generating semantic metadata in the form of RDF tags. You can then use this metadata to develop additional applications to enhance your web services. Check out their document viewer to get a sense of how Calais recognizes and tags named entities in text. You’ll notice that you can also view the RDF version of the text.

In the forums I found an excellent tutorial from Guilhem Vellut for text geotagging using Calais…the demo application can be found here. I’m intrigued by the possibilities for applications combining geotagging and mapping with sentiment analysis. Just off the top of my head:

• Hyperlocal trend visualization


• Political bias/opinion by locality


• Hyperlocal product/company/celebrity opinion analysis

I’d also like to see ebooks with geotagged content. Wouldn’t it be nice to walk in an author’s or character’s footsteps?

In any case, I'm sure there are more applications for the combination of sentiment analysis and geotagging and visualization. Maybe you have some up your sleeve.