#13 - A study tested the performance of 70 pilots, half of

[Administrator]

Please post your questions below!

[lanereuden]

I understand d is totally irrelevant but what in the world is being discussed with e? For this, I could eliminate e only on a hunch—it sounded sophisticated so I thought it was true. I want a better reason than this though.

[lanereuden]

Is this an example of “all of the following resolve the paradox except” question?

[lanereuden]

Doesn’t b make it possible that both groups experienced the same conditions (ie no control group) ? Ie does not contribute as an explanation ?

[Adam Tyson]

This is definitely a Resolve-EXCEPT question! And yes, D is irrelevant because it does nothing to explain why the pilots on diets did worse than they had before or worse than those who did not diet. Not sure it's a "no control group" situation - those not on the diet are the control group. It's more of a "so what?" situation - it resolves nothing because it does nothing. We don't need the correct answer to cause a problem (and a lack of a control group would be a problem for a scientific study). We just need for it to not help to explain what happened.

Answer E helps explain why the dieters did worse than they had before and worse than those who did not diet. Their diet lowered their glucose levels, and glucose is vital to brain function, so they were working with lower-functioning brains! The bit about alcohol in the answer isn't really important, but just a distraction intended to entice people to select it out of confusion.

[loveydog]

Hi thanks for this explanation. I picked D because I thought that if the pilots were aware of the study - it would interfere with the results of the experiment. Why isn't this the case?

Also why does A contribute to an explanation?

Thank you!

[Rachael Wilkenfeld]

Hi loveydog,

We want to explain why the diet causes the poorer performance. It wouldn't be clear why knowing about a study would invalidate it. Sometimes certain medical studies are either blind or double blind, but typically participants know they are participating in a study. A study on diets wouldn't be able to be done blindly, because you know what you eat.

Answer choice (A) gives us an explanation for the poor performance of the dieters. It tells us that the dieters might have been distracted by worries about their weight loss and calorie intake. Just like alcohol, distraction can impair performance--we see that all the time with people who text and drive. Distraction decreases performance.

Hope that helps!
Rachael

[mf2027]

Hi, could someone explain how B contributes to the results, i.e., isnt the correct answer? I thought that it would invalidate the results due to the fact that its effecting the non-dieters as well and we are not given any info on which percent of each are consuming it. Thanks in advance.

[Jonathan Evans]

Hi, mf2027!

Good question! The stimulus stipulates that the impairment was comparable to consuming two alcoholic beverages on an empty stomach.

In the event that members of both groups consumed alcohol prior to the tests and if it is true as the answer choice notes that "dieting increases vulnerability to alcohol's effects," then we may correctly infer that all else being equal the dieters will have increased impairment from the alcohol, as the stimulus notes. Meanwhile the non-dieters may have consumed the alcohol, but they will not be as susceptible to its effects.

This information is sufficient to establish what might be the cause of this difference in performance.

I hope this helps!