The language of truth and falsehood does "invoke ideas of journalists as almost scientific fact-finders." But it isn't just the language of truth and falsehood that bestows upon the art of fact checking an air of science. Journalists who specialize in fact checking do many things that scientists do (but not always). They usually cover falsifiable claims, flicking a wink into Karl Popper's posthumous cup of tiddlies. They always formulate questions and hypotheses about the factuality of the claims that they cover. They usually test their hypotheses against empirical evidence rather than unsubstantiated opinion.
Yet Fact checkers ignore a lot of the scientific method. For instance, they don't replicate (then again, neither do many scientists). Moreover, fact checkers like PolitiFact and The Fact Checker use rating scales that link only indirectly and quite incompletely to the logic of a claim. To illustrate, observe PolitiFact's description of its Truth-O-Meter scale.
By obscuring the reasons why something is false, these ruling scales make it easy to derive factuality metrics like the malarkey score, but difficult to interpret what those metrics mean. More importantly, PolitiFact and The Fact Checker make themselves vulnerable to the criticism that their truth ratings are subject to ideological biases because...well...because they are. Their apparent vagueness makes them so. Does this make the Truth-O-Meter and Pinocchio scales worthless? Probably not. But we can do better. Here's how.
When evaluating an argument (all claims are arguments, even if they are political sound bites), determine if it is sound. To be sound, all of an argument's premises must be true, and the argument must be valid. To be true, a premise must adhere to the empirical evidence. To be valid, an argument must commit no logical fallacies. The problem is that the ruling scales of fact checkers conflate soundness and validity. The solution is to stop doing that.
When and if Malark-O-Meter grows into a fact checking entity, it will experiment with rating scales that specify and enumerate logical fallacies. It will assess both the soundness and the validity of an argument. I have an idea of how to implement this on the web that is so good, I don't want to give it away just yet.
There are thousands of years of formal logic research that stretch into the modern age. Hell, philosophy PhD Gary N. Curtis publishes an annotated and interactive taxonomic tree of logical fallacies on the web.
Stay tuned to Malark-O-Meter, where I'm staging a fact check revolution.