My company, Bitscover by name, is developing a trust rating system for the data that we collect from private sector sources. We don't yet feel confident enough in our "navigation" of government data sources to do this for public sector data, but we are always open to "learning enough" to do this.
Our private sector rating is a composite rating based on two main factors (and other, smaller ones). They are 1) the source or "provenance" of the data and 2) the apparent quality of the data.
1) Provenance: All other things being equal, a source like the New York Times or Wall St. Journal is considered more reliable than say, the local newspaper.
2) Number 1) notwithstanding, a well-reasoned, well-written article in the local newspaper carries more weight than a random "thrown together" article from the Times or the Journal.
3) This is technically under 2), but I'm going to present it separately. If the author of the "local" paper's article was the Editor-in-Chief, and the author of the Times or Journal article was a new, junior staffer, or "no name" writer, that would, of course weigh in favor of the local paper's piece.
So you have a multi factor analysis that figures into a "composite" score.