Q9 - A retrospective study is a scientific

[noah]

I see what you mean, (A) is very tempting!

Let's take a look at this sufficient assumption question. We'll start by finding the conclusion: retrospective studies can't reliable tell us what in the past caused someone to be the way they are. Why not? Because they rely on the subjects' reports about their pasts.

What's the gap? The argument assumes that people's reports about their pasts are somehow flawed. And that's the gap that (C) fills.

What about these awfully-tempting wrong answers?

(A) is most easily eliminated because it brings in "inaccurate reports about the subjects' past." We don't know that the reports that subjects provide are inaccurate. If the argument were something like "since people often give inaccurate reports...these studies are flawed" then (A) would be an assumption (it would probably be a necessary assumption - notice the "depend at least in part" language). Even if (A) simply said "the reliability of a study depends in part on whether it uses subjects' reports of their own pasts" we still wouldn't be able to draw the conclusion. We need to know that if you use these subject-generated reports, the study is unreliable - we don't want to hear that it depends in part. We need a sufficient assumption.

(B) is tricky. It sets up a condition that must exist for these studies to work (there must be a correlation between the past events and the present characteristics). That seems reasonable, but that doesn't get us to the conclusion that the studies are unreliable. For all we know, that correlation always exists.

(D) is probably not tempting at this point - we don't know that the study uses only accurate reports, and we're not interested in concluding that the study is reliable!

(E) is suspiciously extreme - every? What it does is limit these studies to only use subjects' reports of their own pasts. But, how does this relate to the reliability of those studies? Not at all!


#officialexplanation

[jennifer]

I was able to get this answer correct, but was super temped by answer choice A. What is the difference between A and C, besides C being the correct answer? What makes A incorrect? Thank you

[joseph.m.kirby]

The stimulus begins with some background information, defining what a "retrospective study" is. The argument then follows:

P: Retrospective studies of human subjects must use the subjects' reports about their own pasts

-Gap-

C: Therefore, such studies cannot reliably determine the causes of human subjects' present characteristics.


The gap pertains to the studies having to use subjects' reports and to how studies cannot reliably determine the causes of human subjects' present characteristics. We are not told what the problem is with the reports or what causes the studies to be unreliable. We are expected to assume that there is some condition, (C), which makes the conclusion follow.

[dean.won]

I mapped the last sentence of the stim as:

Cannot reliably determine causes of present characteristics --> must use subjects report of own past

And D being somewhat of a contrapositive of the above statement

I know normally it would be hard to conditionally map a cause effect statemeny but i remember seeing some ppl mapping it out for other questions (effect=sufficient, cause=necessary). When is it possible to map a cause effect relationship and when is it not possible?

As for the question, I quickly bubbled C because i knew the answer had to deal with "what about their own reports would make them unreliable?" Was my reasoning correct?

[noah]

I mapped the last sentence of the stim as:

Cannot reliably determine causes of present characteristics --> must use subjects report of own past

And D being somewhat of a contrapositive of the above statement

I know normally it would be hard to conditionally map a cause effect statemeny but i remember seeing some ppl mapping it out for other questions (effect=sufficient, cause=necessary). When is it possible to map a cause effect relationship and when is it not possible?

As for the question, I quickly bubbled C because i knew the answer had to deal with "what about their own reports would make them unreliable?" Was my reasoning correct?

Your reasoning is fine, though you'd still want to work wrong-to-right.

As for diagramming cause and effect as conditional logic, it works when the cause will definitely lead to the effect.

Here, I think a bit less focus on the conditional logic makes sense. The "because" tells us what the premise is, and so the core becomes clear (and, hopefully, the gap).

[gaheexlee]

I was stuck between (A) and (C) because of I thought on sufficient assumption questions, a new keyword in the conclusion HAD to appear in the answer choice?

Isn't the conclusion: "such studies cannot reliably determine..."

Reliability is a new concept isn't it? So I thought since (A) connected reliability with something else, it would be correct over (C). I was bothered by the "inaccurate reports" part in (A) but I thought it was reasonable to assume that the stimulus implied this.

Now I see that this assumption was incorrect, but I'm still confused as to how (C) is correct even though it never mentioned reliability. Any ideas?

[logicfiend]

Sufficient assumption questions are quite formulaic, and you're right, there is a new concept introduced into the conclusion that must be included in the assumption: the subjects reporting about their own past. This is why (C) is correct.

There must be something "bad" about subjects doing the reporting of their own past that makes these studies unreliable. This is the gap that (C) bridges. (A) tries to do with (C) is doing, but fails. It never explicitly says that it is the subjects reporting about their own past that is making these reports unreliable!

I would not get hung up on "reliably" being the conclusion. Understanding the argument and the gap will more successfully bring you to the right answer. Here, reliability does not play a contextual role in the argument.

[KenM242]

So even if (A) had said: "Whether or not a study of human subjects can reliable determine the causes of those subjects' present characteristics DEPENDS (or, 'may depend on', which is even weaker and worse) on the ACCURACY of the reports about the subjects' pasts, (A) would still be wrong? Because the assumption that the argument direly needs is that [the reports provided by the subjects about their own pasts IS inaccurate]?

In other words, unless it is stated that these reports (by the subjects) are inaccurate, it does not matter whether the test relies on their accuracy or not? Because if these reports ARE accurate, then the conclusion as stated in the stimulus cannot follow?


And also, (A) as it is even a weaker version of the modified version above, I presume? First of all, if the study 'may depend' on the reports, that means there is a good chance that the accuracy of these subjects' reports does not matter at all from the first place, which throws the entire argument out the window. And also, 'the extent to which' means that even if the reports are inaccurate, there is still a chance that the study can yield an accurate result, which also undermines the reasoning behind the conclusion.

[ChentuoZ870]

One more question regarding Q9.

I choose C correctly, and understand that A is just stating a logical reasoning in a "X then Y" style, yet not drectly stating Y.

What C makes me hasitate is that when choosing C, we should at least assuming something like "if the material is inaccruate, then the studies cannot reliably...”

Is it OK to make similar assumptions in other questions? Or only under the context of Q9, we can justly make such assumption?