PrepTest 155

The stimulus does mention bias, but there's no issue of cause and effect here. Nobody alleged that the complaining customers became politically biased against the roofer because the roofer mistreated them. So, this isn't a flaw found in the stimulus.

Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Errors in Reasoning

Stimulus Summary:
Klemke the roofer argues that complaints about his roofing company are unfounded, because they all come from his political opponents. But it's perfectly possible that the roofer's company mistreated people with opposing political views. So the complaints are not unfounded after all.

Strategy Overview:

1. Argument or facts? Always argument, so identify premises and conclusions of argument
2. Anticipate why the premises are not enough to prove that the conclusion is true. 
   1. Checking to see if a common logical fallacy is committed is very helpful.
3. Use anticipations to select the answer choice that:
   1. Accurately describes the reason why the premises are not enough to prove that the conclusion is true

Answer Anticipation:
On an Errors in Reasoning question, we should take the time to articulate why the premise or premises aren't enough to prove that the conclusion is true. To help organize our thought process, we can think about the common flaws that arguments commit over and over again.

Upon noticing that an Errors in Reasoning question includes two arguments, an LSAT well-versed in the flaws will immediately think of the possible disputation flaws. And the most common disputation flaw on the LSAT, by far, is the absence of evidence flaw. In one version of that flaw, one speaker will point out that the second speaker's reasoning is bad Typically, the first speaker does this by showing that the second speaker's premises are not enough to justify the conclusion the second speaker drew. The first speaker will then assert that the second speaker's conclusion must also be untrue. This technique is fallacious because the second speaker's conclusion may be true, even if their premises are not good proof. (For instance, I may argue that gravity exists because I heard that there are super-powerful alien magnets in space. You can disagree that my premises are sufficient to prove that conclusion while still agreeing that my conclusion is true.)

This is exactly what happens in this passage. The author refutes the roofer's reasoning (by pointing out the roofer's ad hominem fallacy) and then uses that refutation to conclude that the roofer's conclusion is untrue. But even if the roofer used inadequate premises, the complaints against the roofer could be unfounded. It's entirely possible that the complaints are unfounded and the roofer is making a fallacious argument against the complainers. Sometimes, everyone's a jerk.

Answer Choice Explanation:
Here's our correct answer. It perfectly describes the problem found in the passage. After refuting the roofer's premises, the author then claims that, because the roofer's argument was bad, his conclusion must be false. But even if the roofer made an inadequate argument in favor of his conclusion, his conclusion could still be true.

Key Takeaway:
In Errors in Reasoning questions that feature two arguments, we'll need to be extremely careful. Some incorrect answer choices will point out a flaw in one argument (as (C) and (E) did here) when the question stem will ask us to identify a flaw in the other argument. Reading the question stem carefully and identifying the main conclusion will help avoid this trap.

This is a flaw in the roofer's argument, but it's not a flaw in the author's argument. The author never claimed the roofer's political biases made his argument invalid. In fact, the author pointed out that the customers' biases might not have affected their complaints about the roofing company.

This accurately describes a sampling fallacy, but there's no sampling fallacy in this argument. The argument never made a claim that would require representation from "diverse political outlooks."

When we see "fails to consider" on an Errors in Reasoning answer choice, the question we should ask ourselves is, "Would this weaken the author's argument if true?" The possibility that people whose views diverge are unaware of their disagreement would weaken the roofer's claim — if the complainants weren't even aware of the roofer's political views, they probably weren't biased against the roofer. But this possibility wouldn't weaken the author's view. The author doesn't use anyone's political views or potential bias to support this argument. In fact, the author pointed out one's political views or potential bias isn't good evidence in the first place. Because this answer choice wouldn't weaken the author's argument, it is incorrect.