The makers of the LSAT are very good at creating difficult Logical Reasoning questions. And since they can test new questions in the experimental sections of every LSAT, they can glean a lot about what works against the unwary test taker. The two scored Logical Reasoning sections comprise about half the test, so there are plenty of opportunities to introduce different types and degrees of difficulty along the way.
When the makers of the LSAT create a Logical Reasoning question, they have several chances to make it more challenging. They can write a difficult stimulus, ask a challenging question, and cleverly hide the right answer among several very appealing incorrect answer choices. And they have a lot of ways to make the wrong answers look good: One answer choice might introduce an idea that is very similar to a concept discussed in the stimulus, but different enough to be wrong (this is a Shell Game answer choice, as discussed in the Logical Reasoning Bible), and another might provide completely accurate information that just doesn’t answer the question (a choice that presents a line drawn verbatim from the stimulus could be completely accurate, for example, but not be the right answer to a Main Point question).
One great example of a very appealing wrong answer choice was presented in the second Logical Reasoning section of PrepTest 13, as part of an LSAT question that has become fairly well-known: a beverage company representative is quoted touting the benefits of a new type of plastic rings to hold together six-packs. Unlike standard rings that can suffocate wild animals, the new rings, we are told, disintegrate after just three days in the sun. The speaker concludes that once others follow his company’s lead, the suffocation threat "will be eliminated."
The question that follows asks for the choice that will weaken the speaker's argument, and one very clever wrong answer choice that students tend to find very appealing provides that these new rings actually disintegrate into potentially harmful substances! One reason students often choose this answer is that it’s easy to generalize detriments that these new rings will bring (recall that the representative limited the claim to the elimination of the suffocation threat). Beyond that, though, students have pointed out that this answer really makes the beverage company representative seem rather disingenuous; are these new rings such a great thing for the animals in spite of the fact that they melt into harmful substances? Even if this is the case, considering the fact that the actual claim is limited to the threat of suffocation, it would not be weakened by this choice (the correct answer choice, incidentally, points to the fact that even after the new ring introduction, the old rings will still be around to pose the suffocation threat. This choice directly attacks the conclusion, whose specific claim is that the suffocation threat will be eliminated once others follow this beverage company's lead). This is one of my favorite examples of a very clever challenge hidden among the answer choices.
Image: Danger, courtesy of Shawn Carpenter