Claims of Fact
Claims of fact present verifiable forms of evidence as the supporting foundation for an inferred position statement. In other words, a claim that that which can not be proven by actual facts is, in fact, true or real based on facts that are somewhat pertinent to the issue. For example, the position statement that "grades measure neither intelligence nor achievement," backed with factual evidence like test scores, duplicable research findings and personal testimony.
Claims of fact notwithstanding, the statement can't actually be proven. Intelligence and achievement measurements are, at best, subjective terms that challenge hard definitions. No amount of factual evidence is going to change that.
Nailing down the terms of the position with objective, concrete definitions will strengthen the statement but be advised that an inferred position is poor foundation on which to build an argument.