QUESTION TEXT: Journalist: A recent study showed that people…
QUESTION TYPE: Argument Evaluation
CONCLUSION: Decaf coffee damages connective tissues.
REASONING: The decaf group had worse connective tissues than the caffeinated group.
ANALYSIS: There was no control group in this study. One group drank decaf, the other caffeinated coffee. A control group would drink no coffee at all.
It’s possible that decaf damages connective tissues. It’s also possible that decaf does no damage, and caffeinated coffee helps connective tissues. That could also account for the gap.
The wrong answers all talk about the population in general. We only care about these two groups. Each group drank three cups per day.
It doesn’t matter what other coffee drinkers do – they weren’t part of the group.
___________
- This doesn’t matter. We don’t know if exercise helps or hurts joints. We also don’t know whether this specific group of decaf drinkers exercised. We care about this particular group, not decaf drinkers in general.
- We don’t care what people do in general. We only care about these two groups. They each drank three cups per day.
- CORRECT. This is very relevant. If caffeine slows connective tissue degeneration, they maybe coffee helped the group that drank it. The decaf group didn’t hurt themselves, they just didn’t help themselves by drinking caffeine.
- Same as A and B. We only care about these two groups, not coffee drinkers in general.
- Same as all the other wrong answers. We only care about the two groups, not the general population.
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William says
After doing rather well on other prep tests, I did poorly on this one; mainly due to a tendency to second-guess, expecting some kind of tricky trick out of LSAC when the correct answer, initially chosen, was fairly straight-forward. This is one that I missed. I chose C at first, then went with E, because C looked too easy.
My reasoning lies in a scope shift in the stimulus and the answer. The stimulus “damages tissue,” while the answer says “degeneration of tissue is slowed,” i.e., it assumes some amount of a priori damage. If the tissues are damaged anyway, then merely slowing the degeneration is a very different thing than inflicting some degree of damage, in much the same way that slowing the peeling of paint differs from painting a house. It’s a rate vs. presence shift.
The issue with E is that there is nothing to suggest the manner in which study participants were chosen. At first blush, it appears relevant whether coffee drinkers in the general population would show the same tendencies, as this would add weight to establishing a correlation. Looking at the stimulus again though, it asks for a difference between decaf & regular coffee drinkers, while data that does not reproduce this distinction is virtually worthless. E was a bad choice in a number fo ways.