PT154 S4 Q23 ExplanationSafety expert: Conversing on a cell

Answer choices, explained

1. A

   Correct63% picked this

   Speaking to a driver during a difficult driving situation significantly increases the risk of an accident, unless the

   Why this is right

   Since "unless" can be diagrammed as "if-not" (i.e. "if it is not the case that ..."), we could represent this answer with this conditional: not providing ? talking to driver during diff helpful warnings situation increases risk When we have a "nested unless" conditional, like If X, then Y, unless Z we can add the negated form of Z to get X and ~Z ? Y So another way to think of this answer is, Speaking to driver during difficult driving situation increases risk and ? of accident not helpful warnings When Necessary Assumption answers are conditional, we can ask ourselves, "Did the author make that move?" Sure! The author thinks that talking on a phone is more dangerous than talking with someone in the car, because the person on the phone keeps talking during a dangerous driving situation. So, yes, the author is assuming "If you're talking to the driver (continuing the conversation) when things get difficult, it's more dangerous".

   Skill tested: Necessary Assumption · how this choice captures the argument's function is the move to repeat next time.

   63%
2. B

   Irrelevant Comparison18% picked this

   A driver having a conversation with a passenger in the vehicle during a difficult driving situation is not substantially more likely to have an

   The author's argument is only comparing talking on cell vs. talking to passenger phone while driving while driving This answer is comparing: not talking during vs. talking to passenger difficult situation during difficult situation That comparison is out of scope, since it has nothing to do with the comparison made in the conclusion. If we negated this, it would sound like "talking to a passenger is substantially more dangerous than not talking to a passenger, during a difficult driving situation". That wouldn't weaken the author's argument; it actually seems to agree with the author's argument, since our author thinks that "talking = more dangerous" and thus that "passengers, who can see that they should stop talking = less dangerous".

   18%
3. C

   Out of Scope: believe2% picked this

   People who use cell phones while driving generally believe that talking on a cell phone does not increase their risk

   This argument isn't about what people believe is more / less dangerous. It's only about what is more / less dangerous. This argument doesn't have to assume anything about what people believe.

   2%
4. D

   Opposite, if Anything5% picked this

   Helpful warnings given to a driver in a difficult driving situation are as likely to distract the driver as to help the

   There's no reason to say the author must be thinking that helpful warnings are just as likely to be a distraction as they are to help. If they're helpful warnings, then by definition they're providing some benefit. The author's final sentence makes it seem like passengers are doing something good by either being quiet or offering helpful warnings.

   5%
5. E

   Unknown Comparison11% picked this

   Conversing on a cell phone while driving is no more dangerous than conversing with a passenger in the vehicle who continues to

   This one feels pretty tempting. We know the author thinks that cell phone conversations are more dangerous because the conversationalist keeps talking, so it feels reasonable to think that a talking passenger would be roughly the same element of distraction/danger. But if we negate this, would it weaken? negation: talking on a cell phone while driving is more dangerous than talking to a passenger who keeps talking. No, that would strengthen the conclusion, by making it sound like talking with someone on a cell phone while driving is more dangerous than talking with a passenger. If the negation doesn't weaken (let alone, strengthens), then it can't be a correct answer.

   11%