Hi gmatrix,
wow, that's a big argument!
The most important text is the last sentence and the last clause of the second-to-last sentence.
The last sentence is the conclusion which is "thereforing" from the preceding idea.
So the argument can be paraphrased as:
"Because they ignore anything that doesn't directly bear on their research, there can no longer be any serendipitous findings."
But we can object to the argument: what if findings that an investigator doesn't seek (i.e., serendipitous findings) bear on research.
One way of figuring out the assumption is to defend the argument against an objection. That is, negate the objection. So, the author is assuming that only findings that an investigator purposely seeks (i.e., non-serendipitous findings) can directly bear on research--choice A is correct.
Notice that this is a commonsensical assumption. After all, we are unprepared to think that serendipitous findings can directly bear on research--it doesn't necessarily seem plausible. But precisely because this assumption makes so much sense, it is hard to spot.
We can also use the Kaplan denial test. Let's deny choice A and see what happens to the argument.
Choice A reads:
Only findings that an investiagor purposely seeks (i.e., non-serendipitous findings) can directly bear on research
whose denial is:
Other findings (i.e., serendipitous ones) can directly bear on research
in which case the argument falls apart. Because the argument doesn't survive the denial of choice A, the argument's reasoning depends on choice A.
(Choice D--probably the most tempting wrong answer--is wrong because the author doesn't NEED to assume that ALL scientific investigators (who provide grant sponsors with clear-projections of outcome) receive grants.
Choice B is wrong because we don't care about clear predictions of outcome.
Choice C is wrong because we don't care about what the investigators prefer.
Choice E is wrong because we don't care about what discoveries are the most "valuable.")
Kaplan Teacher in Toronto
