PrepTest 103

Incorrect. How passengers feel is out of scope of whether they're actually safe.

Incorrect. What causes the false positives is out of scope—what matters to a conclusion about the relative safety of planes with and without such systems is whether the false positives present any dangers themselves.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Strengthen with Necessary Premise

Stimulus Summary:
CAR System - Warns pilots where other planes are and tells them to take evasive action
Conclusion - Passengers are safer on planes with than without a CAR System
Wrinkle - CAR Systems frequently give false positives (a warning when there's no plane nearby)

Answer Anticipation:
Let's talk about this stimulus first. It starts with a description of a system, which will almost always be background. From there, it hops right into a premise that's going to support a conclusion in the same sentence—we know that since it starts with "Because." That conclusion is comparative, discussing the relative safety of passengers on planes with and without a specific system. And then it introduces a wrinkle—the system sometimes gives a false alarm.

With the argument outlined, we can hop into the flaw here. We know that the system warns pilots of nearby planes, allowing them to take evasive action and avoid collisions. That seems to support the conclusion that it makes passengers safer!

However, there's no indication that it doesn't have any other impact on the ability of the pilot to work. Maybe the alarm startles pilots and causes them to crash. Maybe evasive action causes more danger than being warned by air control to shift. There's even a note that the system "frequently" has false positives—maybe that itself creates danger.

Since the argument is assuming that any danger of having the system—and dealing with the false positives—is outweighed by the warnings provided by the system, we should look for answers that address alternative dangers, and establish they're less of a big deal than the possibility of collision (which, to be fair, sounds pretty bad).

Answer Explanation:
This answer brings up a possibility that would invalidate any benefit of the system. If the frequent false positives do cause pilots to routinely ignore the warnings, then they wouldn't be enhancing safety, since the pilots are ignoring them. The argument does require that the false positives don't lead to the pilots to ignore legitimate warnings, so this is the correct answer.

Key Takeaway:
Comparative conclusions generally require criteria for making the comparison and a full exploration of that criteria for the compared things. Here, the argument reached a conclusion about safety but discussed only a single aspect of safety. As such, any answer about another aspect of safety was relevant—even one that discusses another safety aspect of something already involved in the comparison.

Incorrect. The argument is about commercial passenger airplanes (and comparable airplanes), so this answer is out of scope.

Incorrect. The argument is about relative safety between different planes, but getting to "safer" doesn't require something to be the "greatest" safety risk, as this answer states. Passengers could be safer on a plane that more easily avoids midair collisions than on a plane that doesn't, even if the greatest safety risk has to do with the process of slowing down once landing on a runway.