#23 - Safety expert: Conversing on a cell phone while

[ashpine17]

For answer choice A, doesn't significantly mean by a lot? if negated, wouldn't it still be possible for conversing on cell phones to be MORE dangerous because it could be true that talking on cell phone is still slightly more dangerous than talking to passengers.

[Rachael Wilkenfeld]

Hi Ash,

Let's start with answer choice (D). If we negate that answer choice, we get that helpful warnings are not as likely to distract the driver. That could mean either that helpful warnings are the same likelihood or less likely to distract than cell phone conversations. The negated form of that answer choice actually potentially helps the argument, so it's not what we are looking for.

Answer choice (A), it's actually easiest to negate by drawing out the conditional. As it's written, answer choice (A) says

speaking to a driver significantly likely to increase risk of accident speaker is providing helpful warnings.

To negate a conditional statement, you say the sufficient condition occurs even without the necessary.

Here, it would look like this: Speaking to a driver significantly likely to increase risk of accident EVEN IF the speaker is providing helpful warnings. That negated form here would hurt the argument. If there's an increased risk of accident even if the talking is helpful, then the author's conclusion that cell phone conversations are more dangerous is weaker. That's the answer choice we are looking for. It doesn't have to destroy the author's conclusion, but just make it less likely. By hurting the evidence provided by the author, the negated form of the answer choice hurts the conclusion. It doesn't really matter that there's a possibility still that the author is correct with the negation. It makes it less likely, which is what we need.

Hope that helps!

[Henry Z]

I still don't get why (B) is wrong.

The conclusion is a comparison between conversing on a cell phone and conversing with a passenger, but the premises are about a comparison between conversing on a cell phone and basically not conversing with a passenger ("a passenger in the vehicle will usually be quiet or even provide helpful warnings in such situations.") I thought it was a concept shift.
From the premises, we only knew conversing on a cell phone is more dangerous than not conversing with a passenger, but the conclusion is about when conversing with a passenger.

To fill the gap, I tried to link the two sides of the concept shift: that conversing with a passenger in the vehicle is no more dangerous than when the passenger is quiet or provides helpful warnings. That is (B). And I do think the negation destroys the argument because if negated, the two sides in the conclusion are incomparable, for we don't know enough about them from the premises.

Where did I go wrong?

[Adam Tyson]

I think you went wrong in assuming that the premises were about NOT conversing with a passenger in the vehicle, when the argument plainly indicates the opposite. The idea is that the passenger with whom the driver is conversing will either stop talking (be quiet) or offer some help. We have no data about what happens when there is no conversation going on in the first place!

[ashpine17]

I still don’t get how unless translates to even if or an exception to the rule. Is that just the way it is all the time? I swear it only comes up here

[Rachael Wilkenfeld]

Ashpine, it's the negation of the condition that translates to the "even if." The conditional itself is written as normal for an unless statement. But in order to negate a conditional, you say the sufficient occurs even if the necessary doesn't.

Let's look at how it works for a simpler example. Take the conditional statement "if it snows, I will stay inside." To negate that we want the opposite idea. That's different than a contrapositive. A contrapositive is the same idea as the original conditional, so you aren't going to take the contrapositive here. You are looking for the logical opposite. A conditional means that if the sufficient occurs, the necessary MUST occur. The logical opposite would be that the sufficient occurs, but the necessary does not. So with this example, it would be it snows but I don't necessarily stay inside.

For answer choice A, we start by looking at the conditional as it is written.

speaking to a driver significantly likely to increase risk of accident speaker is providing helpful warnings.

To negate it, we'd say that it is not required that the speaker provides helpful warnings in order for speaking to the driver to not significantly increase the likelihood of an accident.

If the "even if" language is confusing for you, phrase the original conditional in terms of requirement. To negate that, you'd say the required is not required.

Hope that helps!

[lc1357]

I see why A is the best answer, but I still didn't like it because of the word "significantly." I didn't think it was necessary for speaking to a driver to SIGNIFICANTLY increase risk. Negation test says "Speaking to a driver during a difficult driving situation does not significantly increase the risk of an accident, even if the speaker is providing helpful warnings." This doesn't seem to attack the argument that strongly because it could be true that speaking to a driver can increase the risk to some degree (but not to a significant degree). This allows the argument to still be true. Could someone please explain why "significantly" is necessary or if this line of reasoning is incorrect? Thank you!

[MaxFred25]

I see why A is the best answer, but I still didn't like it because of the word "significantly." I didn't think it was necessary for speaking to a driver to SIGNIFICANTLY increase risk. Negation test says "Speaking to a driver during a difficult driving situation does not significantly increase the risk of an accident, even if the speaker is providing helpful warnings." This doesn't seem to attack the argument that strongly because it could be true that speaking to a driver can increase the risk to some degree (but not to a significant degree). This allows the argument to still be true. Could someone please explain why "significantly" is necessary or if this line of reasoning is incorrect? Thank you!

Hi lc1357. I'm not a PowerScore tutor, but I may be able to help out a bit here.

From my reading, you should negate the presence of providing warnings. My negation for this was "Even if the speaker is providing helpful warnings, speaking to a driver during a difficult driving situation significantly increases the risk of an accident." In other words, providing warnings does not decrease the risk of conversing with a driver. This would destroy the argument - the critical difference between the passanger and the caller is that the passanger is able to provide warnings while the caller is not. Thus, if offering warnings to the driver did nothing to the risk of the accident, as negating answer choice A would posit, the relative superiority of conversing with a passanger as opposed to a caller would be null. In other words, negating answer choice A negates the only provided reason as to why conversing with a passenger is safer than conversing on the phone, thus destroying the argument.

Hope this helps!

[Luke Haqq]

Hi lc1357!

The previous post does well at applying the Assumption Negation technique.

As MaxFred25 notes, with the negation of (A),

providing warnings does not decrease the risk of conversing with a driver. This would destroy the argument - the critical difference between the passenger and the caller is that the passenger is able to provide warnings while the caller is not.

Hopefully that post's explanation makes clear why the word "significantly" isn't problematic in (A). Since the negation would destroy the argument, that confirms that the answer choice is an assumption on which the argument depends.