I didn't mean to insinuate that Popper regarded any idea as suitable until falsified (very sorry for leaving that somewhat inaccurate statement). I was merely throwing Popper out there in contrast to the positivists' verificationism. What I should have stated about Popper's views is that a theory gains in suitability (or verisimilitude) if those observations that would prove the theory false are conducted and the theory is not falsified based on conducting those tests. However, like most things, simple definitions are still lacking in their accuracy so I'll just quote his own words (actually Popper's views transitioned to allowing more truth-content to justify a theory than merely the falsity-content so to be fair this is the view which he seems to have settled upon):
"Assuming that the truth-content and the falsity-content of two theories t1 and t2 are comparable, we can say that t2 is more closely similar to the truth, or corresponds better to the facts, than t1, if and only if either:
(a) the truth-content but not the falsity-content of t2 exceeds that of t1, or
(b) the falsity-content of t1, but not its truth-content, exceeds that of t2."
(Conjectures and Refutations: The Growth of Scientific Knowledge. Routledge, London, 1963. Page 233).
Hope that clears up all misunderstanding. Thanks for pointing at this issue as needing clarification.
Warm regards, Harv