meaning
Consider the following general statement:
Somebody with very little credibility is likely to win a debate.
Given that the opposite is most likely true, how can we best describe the above statement? Is it a fallacy, a misnomer, a misconception, or simply a mistake?
If I were to persist in calling this a fallacy, how appropriate would this usage be? I note that Merriam-Webster defines fallacy as "a false or mistaken idea", which would surely encompass delusional statements like the one above.
Valid word is a difficult thing to quantify. As I've said before, a word exists as long as people use it.
You say in your question that you have read it in literature, so therefore we must conclude that it does exist, and, given the context of its use, is a synonym for quantify.
The meaning according to OED1 is a synonym for quantify, chiefly used in biological or medical contexts, so I feel quite sure that its use is typical.
As can be seen in the above ngram, quantify is more popular than quantitate, but quantitate's use is not insignificant in proportion.
The main difference between the two words is that quantitate is (i.e. can be) used to mean "to perform quantitative analysis upon", which is not really synonymous with quantify. Also, I think it's fair to say, outside of scientific literature, you are unlikely to encounter quantitate.
(1): "quantitate, v.". OED Online. March 2013. Oxford University Press. 20 May 2013 http://www.oed.com/view/Entry/155922?redirectedFrom=quantitate.
It sounds like a restatement of Avoiding the Issue
Avoiding the Issue
shifting attention away from the issue at hand.
Best Answer
I don't think your example is a fallacy, a misconception or a misnomer. It's just false.
To be a fallacy, it would have to be believed - the world is flat was a fallacy for many years, but is no longer (because no one, to my knowledge, really believes it anymore).
It may be a misconception, which is more or less an incorrect understanding of something, but again, who believes the viewpoint in your example? When you call something a misconception, you're implying that more than one random individual advocates the flawed notion.
A misnomer is something else altogether; it indicates a misapplied or inappropriate name for something. Nothing in your example is named/misnamed.