Unfortunately you quickly run into who-watches-the-watchers problems with these sorts of things.
The format of politifact, for instance, is quite open to being abused for political bias; all you'd need to do would be to pay more attention to the falsehoods coming from one side of politics than the other.
I'm also not convinced by the many shades of truth they have from 'true' to 'mostly true' to 'barely true' to 'false' to 'pants on fire'. While I concede the need for middle grounds between true and false when dealing with vague statements, I'm not sure how "barely true" differs from "half true" or "false" differs from "pants on fire". It would be interesting to run through the archive and see if you could pick up any clear bias in terms of who gets what ratings.
1. While I haven't read every claim, they explain all the ones I have, giving their reasons for 'barely true' and the other gray areas. It usually makes sense, and is a refreshing change from binary, accusatory nature of most political discourse these days.
2. I haven't picked up any clear bias, otherwise I would have ditched them a long time ago like I do most other politically biased publications. But an experiment on their data would certainly be interesting.
3. I was going to suggest the site might be a little harder on the current president, but actually Obama is doing alright on the promises scale, so I don't know.
The format of politifact, for instance, is quite open to being abused for political bias; all you'd need to do would be to pay more attention to the falsehoods coming from one side of politics than the other.
I'm also not convinced by the many shades of truth they have from 'true' to 'mostly true' to 'barely true' to 'false' to 'pants on fire'. While I concede the need for middle grounds between true and false when dealing with vague statements, I'm not sure how "barely true" differs from "half true" or "false" differs from "pants on fire". It would be interesting to run through the archive and see if you could pick up any clear bias in terms of who gets what ratings.