Q8 - Satellite navigation systems

[ohthatpatrick]

Question Type:
Strengthen

Stimulus Breakdown:
Conclusion: Satnavs save fuel and promote safety.
Evidence: when you use satnavs to go someplace new, you go a route that is 7% shorter than when you don't use the satnav. And, since you don't need to take your eyes off the road to check a paper map, you're driving more carefully than a driver w/o satnav.

Answer Anticipation:
What are some possible objections? Has the author convinced us that satnavs both save fuel and promote safety? Well, the first problem is that the evidence ONLY concerns trips to NEW places. We don't have any information about how satnavs impact trips to FAMILIAR places. Since the majority of car trips we take are to familiar places, we would want to know whether satnavs are also safer and more fuel efficient (or at least equally safe and fuel efficient) on familiar trips. Other than that, possible objections could tell us that satnavs cause people to use more fuel for some reason (they are emboldened to take more long trips? they drive at a less efficient fuel rate, maybe speeding up more than they would otherwise?) or cause people to drive less safely for some reason (their brains aren't actively thinking about the route so they go into autopilot? the sounds of the satnav distract them from hearing sounds of nearby cars / pedestrians?) Our correct answer will rule out an objection or supply additional evidence that makes satnavs sound safer and more fuel efficient.

Correct Answer:
E

Answer Choice Analysis:
(A) This doesn't touch on saving fuel or driving more safely. The demographic breakdown of who's more likely to use satnavs in a specific scenario doesn’t tell us whether those people are safer, more fuel efficient as a result of using the satnav. Even if 99% of people do NOT use satnavs, the conclusion could still be correct in arguing that satnavs, when used, save fuel and promote safety.

(B) This seems to hint that people who drive gas guzzlers would be more likely to want satnavs, since satnavs seem to find a route that is 7% shorter than without satnavs. But who cares about which type of driver has the most motivation to use a satnav? We're only analyzing the RESULTS of using a satnav (safer? less fuel?), not the motives.

(C) This is just like the first two. It's giving us a way to figure out who is more or less likely to use satnavs. But we don't care about the factors affecting whether or not you use a satnav. We just care about whether the results of using one are saving fuel and promoting safety.

(D) This answer finally deals with driving to FAMILIAR destinations. However, it doesn't compare drivers with satnavs to drivers without satnavs. It merely says that drivers with satnavs are unlikely to even use the satnav. So it's not helping us judge whether satnavs are better/worse/same when it comes to fuel/safety on FAMILIAR trips.

(E) Yes, this helps. It simply adds another fact that supports the conclusion. It's saying ANOTHER way in which satnavs can promote safety is that drivers are less likely to suddenly switch lanes or make other risky maneuvers. We have to assume that satnavs "which announce directions as you drive" = "given directions as needed". But nothing else comes close to adding credence to the claim that satnavs save fuel or promote safety, so this is the best we have.

Takeaway/Pattern: Because the argument failed to consider what happens on FAMILIAR trips, some of these comparisons in the wrong answers probably appealed to students in a confused way. "MAYBE this answer hits on an important distinction?" But if you continually remind yourself that the truth value of the conclusion is simply to compare the fuel/safety results of using satnav vs. not using it, only (E) seems to bring up anything in the ballpark of whether people's satnav driving is saving fuel or increasing safety.

#officialexplanation

[skullastic]

Hi,

I narrowed down to (A) and (E) through POE, but had trouble picking which is the better answer. I ended up choosing (A) because while the premise is about ppl who do use satnavs, the conclusion sounded like it was about benefits of satnav systems in general (to the society maybe?). Wouldn't the conclusion not follow if nobody/few used satnav at all?

Also, one problem I have with (E) is: so what if people sometimes are less likely to follow the directions? Didn't the study show that it help to shorten drives and drive more carefully overall (after taking account for the fact that people sometimes do not follow per the answer choice)?

Any insight on this would be super helpful. Thanks!

[lunazhuyu]

Hi,

I narrowed down to (A) and (E) through POE, but had trouble picking which is the better answer. I ended up choosing (A) because while the premise is about ppl who do use satnavs, the conclusion sounded like it was about benefits of satnav systems in general (to the society maybe?). Wouldn't the conclusion not follow if nobody/few used satnav at all?

Also, one problem I have with (E) is: so what if people sometimes are less likely to follow the directions? Didn't the study show that it help to shorten drives and drive more carefully overall (after taking account for the fact that people sometimes do not follow per the answer choice)?

Any insight on this would be super helpful. Thanks!

Hey I know it's way too late but I just have a few thoughts on your post. I initially chose A, but on blind review I got it correct.

For A, the same reason(it represents a general trend in ppl) also applies in other answer choices. What makes it weak is 1) the topic, still tangling with the novel destination topic but adds no credit to the whole safety/fuel efficiency issue, and 2) the language, such as "more likely"/"often", etc.

For E, it talks about the system would probably increase safety, which adds credit to the argument.

Hope that helps.