A study examining ninety large cities found that in those with more

Question

A study examining ninety large cities found that in those with more kilometers of bicycle paths and roadway bicycle lanes per capita, higher percentages of the population commute to work by bicycle. For this reason the study concluded that adding bicycle paths and lanes is an effective way to encourage commuters to bicycle rather than drive.

Which of the following, if true, would most weaken the reasoning in the study?

A) The higher the percentage of a city's population commutes by bicycle, the stronger political pressure there is for the city to add bicycle paths and lanes.
B) A large percentage of urban bicycle commuters commute via roadway bicycle lanes but use bicycle paths mainly for recreation.
C) Even in communities with extensive bicycle paths and roadway bicycle lanes, many commuters drive rather than bicycle to work because of the perceived danger of bicycling in traffic.
D) On average, cities with climates more pleasant for bicycling have fewer kilometers of bicycle lanes and paths per capita than those with harsher climates.
E) City residents are unlikely to commute along bicycle paths or lanes that do not provide direct, efficient routes between their homes and their workplaces.

MartyMurray · Accepted Answer

A study examining ninety large cities found that in those with more kilometers of bicycle paths and roadway bicycle lanes per capita, higher percentages of the population commute to work by bicycle. For this reason the study concluded that adding bicycle paths and lanes is an effective way to encourage commuters to bicycle rather than drive.

The conclusion is the following:

adding bicycle paths and lanes is an effective way to encourage commuters to bicycle rather than drive

The conclusion is supported by the following evidence:

in those (cities) with more kilometers of bicycle paths and roadway bicycle lanes per capita, higher percentages of the population commute to work by bicycle

We see that the reasoning is basically that since, where there are more bike paths and lanes, higher percentages of the populations commute by bicycle, adding bike paths is a way to cause people to commute by bicycle.

In other words, those conducting the study observerd a correlation between bike paths and people commuting by bicycle and concluded that the first causes the second.

Which of the following, if true, would most weaken the reasoning in the study?

This is a Weaken question, and the correct answer undermines the support that the evidence provides for the conclusion.

A) The higher the percentage of a city's population commutes by bicycle, the stronger political pressure there is for the city to add bicycle paths and lanes.

This choice is interesting.

The evidence supporting the conclusion is that, where there are more bike paths and lanes, higher percentages of commuters use bicycles.

So, what if this choice is true?

In that case, it may be that, even though the premise is true, adding bike paths and lanes does not cause people to commute by bicycle. Rather, it could be that a city's already having many bicycle commuters causes there to be many bike paths and lanes. After all, according to what this choice says, all those bicycle commuters would put political pressure on city management to add bicycle paths and lanes.

In that case, we'd still see a correlation between the number of bike paths and lanes and the percentages of commuters using bicycles, but the cause and effect could be the reverse of that assumed by the reasoning of the study with people commuting causing the addition of bike paths.

So, this choice undermines the case for the conclusion that adding bike paths and lanes would cause people to commute by bicycle by providing reason to believe that the availability of paths and lanes does not necessarily cause people to do so.

Keep.

B) A large percentage of urban bicycle commuters commute via roadway bicycle lanes but use bicycle paths mainly for recreation.

This choice doesn't affect the argument because it just qualifies what we know.

Given what this choice says, we now know that some commuters use bike lanes rather than bike paths to commute. OK, great, but the paths and lanes are still used by commuters. So given what this choice says, it makes sense that adding bike paths and lanes will cause more people to commute by bike.

Eliminate.

C) Even in communities with extensive bicycle paths and roadway bicycle lanes, many commuters drive rather than bicycle to work because of the perceived danger of bicycling in traffic.

This choice is tricky because it could seem to indicate that adding bike path and lanes won't help because people won't use them.

Notice, however, that the fact that "many commuters" won't use bike paths and lanes doesn't mean that adding paths and lanes won't make a difference. After all, as long as SOME people decide to commute by bike because paths and lanes are available, adding paths and lanes could cause people to commute by bike.

In fact, we know from the passage that some people do commute by bike and that, the more paths and lanes there are, the more people commute by bike. So, the fact that many other people won't commute by bike doesn't mean that adding bike paths and lanes won't make a difference.

Eliminate.

D) On average, cities with climates more pleasant for bicycling have fewer kilometers of bicycle lanes and paths per capita than those with harsher climates.

This choice strengthens, rather than weakens, the support for the concusion. After all, we already know that cities with fewer bicycle lanes have lower percentages of commuters who bicycle. Now, we're finding out from this choice that the cities with fewer bike paths and lanes have lower percentages of commuters who bicycle even though they have more pleasant weather.

We'd expect pleasant weather to cause people to commute by bicycle. So, that fact that people in these cities don't commute by bicycle even though there's pleasant weather makes us even more convinced that bike paths and lanes make the difference.

After all, there are more people commuting where there are more bike paths, even though the weather isn't as pleasant there.

Eliminate.

E) City residents are unlikely to commute along bicycle paths or lanes that do not provide direct, efficient routes between their homes and their workplaces.

This choice is tricky because it could seem to indicate that commuters won't use bike paths and lanes if they are added. So, it could seem to indicate that adding bike paths and lanes won't cause people to commute by bike.

So, to avoid choosing this choice, we have to notice a key aspect of it. The point of this choice is basically that, if bike paths and lanes don't go where people want to go, people won't use them. OK, great. No surprise there.

All the same, notice that people won't use other means of travel either if the other means won't get them to where they want to go, and this choice doesn't say that commuters won't use bike lanes in general. So, this choice may very well be true, and it could still be the case that adding bike paths and lanes that go where people want to go will cause people to commute by bike.

So, this choice doesn't weaken the case for the conclusion.

Eliminate.

Correct answer:  A

sayan640 · Answer

So more no of paths were added because of political pressure. Paths were not added to encourage residents and hence adding paths may not be an effective way to encourage cycling. 
 KarishmaB   MartyMurray  I was really confused between A and E. Can you please explain the underlying concept for these kinda questions?  AjiteshArun

Posted from my mobile device

KarishmaB · Answer

The underlying concept is correlation vs causation. A correlation was found between A and B and it was concluded A causes B (adding more bicycle paths leads to more commuters biking)
How can you weaken it? By saying that instead B could have caused A.

Because of more commuters biking, more paths were added (due to intermediate reason of political pressure).

sayan640 · Answer

Thank you  KarishmaB .
Any apparent reason to quickly eliminate option E ? C is also quite close.

Jayam12 · Answer

KarishmaB  how do I eliminate option C? I was really confused between A and C

Ulisse001 · Answer

The conclusion states: More bicycle paths will encourage more people to switch from driving to using bicycle (aka there will be an increase in the percentage of people using bicycles). Support: In cities with more km of bicyle paths a higher % of people use bicycles to go to work.

C tells us that EVEN in cities with lots of bicycle paths MANY people prefer driving rather than using a bicycle. 
What MANY people prefer is irrelevant. The argument only concerns whether there will be an increase in the percentage of people using bicycles. Thus, C is irrelevant.

If I made any mistakes I would to be corrected.

Shreya0005 · Answer

Notice that the conclusion is about  adding bicycle paths and lanes  in general. Option E doesn't say that adding paths  doesn't  encourage bicycling. It simply says  poorly designed paths won't .
In other words, E introduces a  condition for effectiveness , not evidence that the observed correlation is misleading.

So, Even if E is true, the correlation could still exist because cities with more bike lanes also tend to have  well-placed  bike lanes. 
The study's conclusion could still be perfectly correct.

You can think of it as: E gives just a special scenario in which para's reasoning will be refuted. But in general, it may be so.

A study examining ninety large cities found that in those with more

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