Reading Usable Help
@UsableHelp on Twitter
Gordon R. Meyer
Mining visual data to improve documentation
CUNY sociology professors Juan Battle and Bill Kornblum had their graduate students mine Flickr for visual data about how people utilize the campus. It's a brilliant idea, and Flickr makes for a good data source thanks to its own culture of metatagging and support for geo locations. See Flickr for Visual Data Research and Analysis for details of their work.
Here's an experiment you can try. Go to Flickr and search for the name of a product you document. You might be surprised at the results. I found numerous screenshots, and some photos of people using or being taught how to use the software. Browsing through these, the context revealed several things that users seemed to be having trouble with, and also some inspiring things they've created. Consider it a a very low-budget bit of field research.