You are right to be confused. Even Nobel Laureates who signed their names to a document affirming that evolution was a fact, were confused.
An hypothesis is an idea that in science, is subjected to experimental testing. As testing continues and the outcomes of testing are affirmative, an hypothesis evolves into a theory.
Facts (lit. things done or seen) are the data that go into the testing of a theory. Although one hopes such data are true, they are neither necessarily more nor less objective than the theory they are being used to support.
The Harvard astronomer Harlow Shapley probably explained this distinction best: "A hypothesis or theory is clear, decisive, and positive but it is believed by none but the man who created it. Experimental findings [facts] , on the other hand are messy, inexact things which are believed by everyone except the man who did the work."
Ann Roe said" I think many scientists are genuinely unaware of the extent, or even the fact of...personal involvement, and themselves accept the myth of impersonal objectivity"
Heisenberg asserted that only observable magnitudes must go into a theory and chided Einstein that he himself had stressed this in formulating the theory of gravity. Einstein's response was classic: "Possibly I did use this kind of reasoning but it is nonsense all the same. Perhaps I could put it more diplomatically by saying that it may be heuristically useful to keep in mind what one has observed. But on principle it is quite wrong to try founding a theory on observable magnitudes alone. In reality, the very opposite happens. It is the theory which decides what we can observe"
It is absurd to define evolution as a "fact" without defining what one means by evolution. Evolution can mean anything from a change (no matter how small, or in what direction) in an organism, to molecules-to-man evolution. Few evolutionists bother to draw a distinction between what can be observed (change) and what their theory says could result from that change (molecules-to-man). This is more than an oversight, since it offers a convenient shelter for those who would promote evolution. One can always fall back to the observable (change), when assalted on the theoretical (molecules-to-man).
Some parts of what is encompassed in the term "evolution" are indeed facts. We can observe change in organisms, we can even, by selective breeding, bring about such changes, often much to our benefit.
But molecules-to-man evolution is in another realm altogether. Because it cannot be directly observed, it must be inferred from the most indirect types of evidence.
Ó 2010 Arthur V. Chadwick, Ph.D.