Sports psychologist (MGMAT)

[Yuguang]

"I just found there is a "MGMAT" setction". But I failed to move this post there.... sorry

Sports psychologist: Competing against other athletes can have a positive effect on athletic performance, even when the outcome of the competition is inconsequential. Two groups of amateur cyclists adhered to the same training program, but members of one group were provided with objective data on their performance and the performance of the other group members, while the second group was given no information. The cyclists who were able to compare themselves to other group members had a significantly greater average improvement in strength and speed during the program than those who were given no data.

Which of the following, if true, most strongly supports the psychologist’s interpretation of the study?

A. Athletes who frequently compete against others are more likely to adhere closely to a training program than those who rarely or never compete.

B. When members of a third group of cyclists were provided with data on their own performance but not on that of other group members, they performed no better than those who received no data.

C. Cyclists in the study who scored higher on psychological tests of competitiveness performed better on the fitness tests than those who earned low scores.

D. Stronger amateur cyclists are more likely than weaker cyclists to choose to participate in competitions.

E. All cyclists in the group that was given data improved their performance significantly during the training program, while several cyclists in the group that was given no data failed to improve at all.

Instructors, this is from MGMAT and OA=B.
My choice was E.

In E, it says "all without any exception have improved significantly but some in other group failed to improve". It is possible that those data helped improve the performance (because all without any exectpion). And it provides a comparison of the status before they were given with after.

So, why is it wrong? Thanks a lot.

[Sage Pearce-Higgins]

Answer choice E is a classic trap: it strengthens the results of the study, but not the psychologist's explanation. Let me give you a simpler example:

Sage and Stacey played each other at table tennis. However, before the game, Sage drank two strong coffees. Clearly, Sage won the game because he'd drunk coffee beforehand.
Which of the following strengthens the claim that the coffee helped Sage to win?
(A) Sage won by a significant margin.
(B) When they played the day before - no-one had drunk any coffee before the match - Stacey beat Sage.

Hopefully you can see that the second one would be the correct answer. In this simple example, you probably spotted the 'gap' in the argument: we know that Sage won the game, but was it because of the coffee? Perhaps he's simply a better player. Answer (A) repeats and clarifies the situation, but doesn't affect the explanation.

Something similar is going on in this problem. We already know that the cyclists with data performed better, and answer E simply clarifies that. However, was it, as the psychologist claims, because they were competing against other cyclists, or was there some other reason? Note that the other cyclists had no data at all. Perhaps the data that made a difference were the data about their own performance. Answer B plays on this gap. One takeaway here is to think carefully about multiple causes in CR problems.

[Yuguang]

Thank you and I've got your point.

As far as I can understand, it is a cause-and-effect problem. The intended meaning of the questions is to correlate "given data" with "to win". To support (or weaken), we can add or eliminate that factor to see the result.

in E, the intended meaning of the option is to say "the ones given data improved a lot", not a meaning of comparison or clarifying the factors.

Sometimes, I just found I was confused when I saw the question at the first time. At the time when I reviewed question again in calm, I can understand the meaning better, or with a higher accuracy. Any suggestion for this unexpected behavior? Is it because I was not that proficient with those rationale?

[Sage Pearce-Higgins]

I'm glad to see you reflecting on the problem. GMAT arguments often involve cause-and-effect, and I would describe this kind of situation as a "correlation-causation flaw". Simply because two phenomena are statistically correlated doesn't mean that one causes the other. You can Google this for further description and examples.

In general, it's a great idea to make links between CR problems. Look for other examples of arguments involving correlation-causation, and, in general, watch out for conclusions that make claims about cause-and-effect.

[Yuguang]

Thank you! Learn harder.

[Sage Pearce-Higgins]

You're welcome.

[DevikaC983]

Does E also not convey that everyone in the group that had data on competition perform better? As the question mentions about average improvement, it could be biased if there is a scenario where only 1 member improves significantly, and the performance of everyone else remains the same. So, E mitigates that scenario by contending that the performance of all the members in the group improved.

Not sure where I am wrong here.

[esledge]

Does E also not convey that everyone in the group that had data on competition perform better? As the question mentions about average improvement, it could be biased if there is a scenario where only 1 member improves significantly, and the performance of everyone else remains the same. So, E mitigates that scenario by contending that the performance of all the members in the group improved.

Not sure where I am wrong here.

Choice E offers more detail on the premise that we are already relying on (that "The cyclists who were able to compare themselves ... had a significantly greater average improvement in strength and speed during the program than those who were given no data."). In other words, choice E just quantifies this premise a bit more.

But choice E does not further strengthen "the psychologist's interpretation of the study," which is that competing improves athletic performance. The given argument is that:
Premise: having data --> better performance
Conclusion: competing --> better performance
The weakness in the "psychologist's interpretation" is that "having data" is not explicitly the same as "competing" over that data.

You need a choice that ties "having data" and "competing" together (as B does), rather than just offering more detail about "having data" (as E does).