Logical reasoning PrepTest 134 · Section 2 · Question 13

Incorrect. While the author of this argument has shown that their evidence isn't definitive, it's too much to say that they have no evidence for their viewpoint. The carefully designed nests may show that the hadrosaurs watched their young for a while after birth even if crocodiles with similar nests don't.

Incorrect. This answer is way too extreme in saying that we will "never" be able to reach a conclusion here. The viewpoint of some paleontologists based on one piece of evidence isn't proven with certainty, but there could be other information that would allow a conclusion to be drawn, or a future method that would allow it (Jurassic Park, anyone?).

Incorrect. This answer falls into the "opposing point is wrong" category of author opinion on an opposing point. While the author believes the paleontologists's evidence doesn't prove their conclusion, that's not enough to conclude that the opposite of that conclusion is true—i.e., they're wrong. Reaching this opposing conclusion would be an absence of evidence flaw.

Incorrect. The stimulus relies on a comparison between hadrosaurs and crocodiles, not hadrosaurs and other dinosaurs.

Correct. Argument or Facts:
Facts

Question Type:
Argument Completion

Stimulus Summary:
Paleontologists — Hadrosaur kids were in well—designed nests, so some dinos guarded their young for a while.
Pivot — Similar nests are made by modern crocs, who don't guard their young for a while.
Therefore — __________.

Answer Anticipation:
This argument introduces a viewpoint in the opening line ("Some paleontologists. . . "), and when that happens, the author is almost certainly going to pivot away from it. This common argument structure has a conclusion that reflects the author's opinion of that opposing point, so we should already be anticipating what that opinion is. In general, the opinion is either that that viewpoint isn't fully supported, is based on faulty logic, or is wrong.

Here, the author pivots ("But") to a comparison to a modern example—crocodiles. How does that modern example deal with the opposing point? It calls into question the connection between the premises and the conclusion. Sure, hadrosaurs had these nests, and those nests might suggest that they watched their young for a while, but there exists a modern example where similar nests are associated with different behavior.

So circling back to our earlier anticipation of potential answers, does this modern disanalogous situation show that the conclusion isn't fully supported, that it's based on faulty logic, or that it's wrong? It's not enough to show that the conclusion is false—after all, the hadrosaurs may be different in some key way from the crocodiles. It doesn't call the logic of the argument into question—that would involve pointing out a logical flaw in the argument. Instead, it says that the evidence the paleontologists rely on doesn't fully establish their conclusion, because there's a similar situation where the conclusion doesn't follow. Let's find an answer reflecting that opinion.

Answer Explanation:
This answer highlights that the comparison to modern crocodiles shows that the nest evidence isn't very strong—it might suggest that, like crocodiles, that the hadrosaurs didn't watch their young for very long. By reflecting the correct level of disagreement between the author and the opposing point, this answer is correct.
Key Takeaway:
In general, when a viewpoint is introduced in the first line of an argument, the author is going to pivot away from that viewpoint. When that happens, her opinion of the viewpoint is the main point of the argument. And, in general, that viewpoint will fall into one of three categories—it's wrong; it's unproven; it's based on faulty logic.