The Twindex

Can we tell anything about public opinion from monitoring Twitter?  A new service (see below) assumes that we can.  Maybe, but be wary.  As we note in our chapter on public opinion, any measure of sentiment that depends on "spontaneous" expressions (e.g., Internet petitions, mail to congressional offices, phone-in polls) is subject to manipulation. 

Wired reports:

Twitter launched a new service on Wednesday called the Twitter Political Index, or Twindex. By applying highly tuned algorithms to Twitter’s fire hose of data, the service offers a real-time look at voters’ moods, and scores which presidential candidate is trending up (and who is trending down) day to day.

Twindex is a joint effort between Twitter, Topsy, and two polling groups, the left-leaning Mellman Group and the more conservative NorthStar Opinion Research. The collective goal is to dive into Twitter’s deep trove of data, and pull up insights faster than Gallup and other traditional polling companies. Expect to see Twindex results referenced in all political news and commentary as we head into the presidential election.
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Here’s how it works.

Topsy uses Twitter’s high-volume fire hose of data to look at every tweet in the world, and establish a neutral baseline. Separately, it looks at all the tweets about Barack Obama and Mitt Romney, runs a sentiment analysis on them, and compares this analysis to the baseline. It looks at three days’ worth of tweets each day, weighting the newer ones higher than then older ones. It then returns a numerical score for each candidate based on how tweets about the individual compare to all tweets as a whole. A completely neutral score would be 50. Anything above that is a net positive, while lower is a net negative.

So, for example, if Obama has a score of 38, that would mean that tweets about him are more positive than 38 percent of all other messages on Twitter.