Quoted from the site:

At the core of We Feel Fine is a data collection engine that automatically scours the Internet every ten minutes, harvesting human feelings from a large number of blogs. Blog data comes from a variety of online sources, including LiveJournal, MSN Spaces, MySpace, Blogger, Flickr, Technorati, Feedster, Ice Rocket, and Google.

We Feel Fine scans blog posts for occurrences of the phrases “I feel” and “I am feeling”. This is an approach that was inspired by techniques used in Listening Post, a wonderful project by Ben Rubin and Mark Hansen.

Once a sentence containing “I feel” or “I am feeling” is found, the system looks backward to the beginning of the sentence, and forward to the end of the sentence, and then saves the full sentence in a database.

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