A city council is considering implementing a new bicycle-sharing program to reduce traffic congestion and carbon emissions. A proponent argues that similar programs in other major cities have led to a 10% reduction in peak-hour vehicular traffic. Which of the following, if true, would most seriously weaken the proponent's argument that the program will reduce traffic congestion in *this specific city*?
- AThe city's public transportation system is already extensive and highly utilized during peak hours.
- BThe terrain of this city is significantly more hilly than that of the cities where the program was successful.
- CThe cost of maintaining the bicycle-sharing fleet is projected to be 20% higher than initially estimated.
- DA recent survey indicates that most residents commute short distances, making cycling a viable option.
Show answer & explanationAnswer & explanation
Correct answer: B. The terrain of this city is significantly more hilly than that of the cities where the program was successful.
The proponent uses an analogy to other cities to support the claim that the program will reduce traffic congestion in *this specific city*. Option B highlights a key difference (hilly terrain) between this city and the reference cities. This difference could make cycling less attractive and therefore less effective in reducing vehicular traffic, thus weakening the analogical argument.
Why the other options are wrong
- A. An extensive public transportation system might reduce the need for cycling, but doesn't directly challenge the *applicability* of the program's success from other cities due to a *difference* in conditions.
- C. Cost is irrelevant to whether the program will reduce traffic congestion.
- D. This option *strengthens* the idea that cycling is viable, which is the opposite of weakening the argument.
Challenging Analogical Arguments
To weaken an argument based on analogy, identify a significant dissimilarity between the two things being compared that would make the conclusion drawn from the analogy invalid.
- Analogies assume similarity in relevant aspects.
- Look for crucial differences that impact the outcome.
- The difference must be relevant to the conclusion being drawn.
Memory trick: Just because one twin likes apples doesn't mean the other will if they're allergic!