Investigating thousands (or millions) of documents by visualizing clusters

This is a recording of my talk at the NICAR (National Institute of Computer-Assisted Reporting) conference last week, where I discuss some of our recent work at the AP with the Iraq and Afghanistan war logs.

References cited in the talk:

  • “A full-text visualization of the Iraq war logs”, a detailed writeup of the technique used to generate the first set of maps presented in the talk.
  • The Glimmer high-performance, parallel multi-dimensional scaling algorithm, which is the software I presented in the live demo portion. It will be the basis of our clustering work going forward. (We are also working on other large-scale visualizations which may be more appropriate for e.g. email dumps.)
  • “Quantitative Discovery from Qualitative Information: A General-Purpose Document Clustering Methodology.” Justin Grimmer, Gary King, 2009. A paper that everyone working in document clustering needs to read. It clearly makes the point that there is no “best” clustering, just different algorithms that correspond to different pre-conceived frames on the story — and gives a method to compare clusterings (though I don’t think it will scale well to millions of docs.)
  • Wikipedia pages for bag of words model, tf-idf, and cosine similarity, the basic text processing techniques we’re using.
  • Gephi, a free graph visualization system, which we used for the one-month Iraq map. It will work up to a few tens of thousands of nodes.
  • Knight News Challenge application for “Overview,” the open-source system we’d like to build for doing this and other kinds of visual explorations of large document sets. If you like our work, why not leave a comment on our proposal?

Overview: a tool for exploring large document sets

This Associated Press, my employer, has submitted the following proposal to the Knight News Challenge, reproduced here because the original on Knight’s site eats the paragraph breaks and doesn’t display the full-res image.

click for larger image, or awesome hi-res version

Describe your project:
Overview will be a tool for finding stories in large document sets, stories that might otherwise be missed. We will use the AP’s newsroom as a real-world environment to design and build a system to help journalists clean, visualize, and explore very large document sets — tens or hundreds of thousands of pages. We want to build a tool to answer the question, “what’s in there?”

Continue reading Overview: a tool for exploring large document sets