It looks like one thing they track is how much you vote, compared to the average and compared to the 90th percentile of absenteeism. It looks like Capuano got close to that during parts of 2000 and 2001, but has been better (though not generally better than the mean) recently. There isn't any separation of significant v. insignificant votes there.
Since I was also wondering what that might mean...
http://www.govtrack.us/congress/person.xpd?id=400063
It looks like one thing they track is how much you vote, compared to the average and compared to the 90th percentile of absenteeism. It looks like Capuano got close to that during parts of 2000 and 2001, but has been better (though not generally better than the mean) recently. There isn't any separation of significant v. insignificant votes there.