#9 - A retrospective study is a scientific study that tries

[Administrator]

Complete Question Explanation

Justify the Conclusion, CE. The correct answer choice is (C)

Retrospective studies are those which seek to link a participant’s past experiences (from before the
beginning of such a study) with his or her present characteristics, looking for connections to show
the causes that led to current attributes. Based on the fact that these studies rely on participants to
report on their own past experiences, however, the author of this stimulus concludes that such studies
cannot reliably determine the causes of present characteristics:

• Premise: Retrospective studies rely on subjects to report on past experiences
  
  Conclusion: Retrospective studies can’t reliably determine causes of present characteristics

The author clearly believes that studies that rely on people to report their past experiences cannot
provide reliable information regarding the past causes of participants’ present characteristics.
The question stem that follows the stimulus is one that is often mistaken for an Assumption
question, because it asks for the assumption that will enable the author’s conclusion to be properly
drawn. What this really means, though, is that the correct answer choice will Justify the author’s
Conclusion.

Applying the Justify Formula, we can pinpoint the rogue elements that must be linked for the
conclusion to be properly drawn: The right answer will likely provide that studies which rely on
subjects to report on their past experiences cannot reliably determine the causes of participants’
present characteristics.

Answer choice (A): This answer choice might look quite enticing at first, because it opens with a
discussion of reliable determination of a cause. However, this choice is not applicable because it
deals with inaccurate reports. The author does not assert that such reports (which are self-reported
by subjects) are necessarily inaccurate, but rather that they are unreliable (a subtle but important distinction: if, based on a coin flip, someone claims that tomorrow will be rainy, I would probably
take issue with the reliability of such a method, even if it does actually rain the following day).

Answer choice (B): This confusingly worded and incorrect answer choice basically says that the
causes of present characteristics cannot be determined unless such characteristics correlate with past
experiences. This choice fails to link the element of self-reporting with the element of unreliability,
so it cannot be the correct answer choice to this Justify the Conclusion question.

Answer choice (C): This is the correct answer choice, and the one which links the prephrased
element of self reporting with that of lacking reliability. If, as this answer choice provides, selfreported
information is likely to be inaccurate, this justifies the author’s conclusion that retrospective
studies (which use such self-reported information) cannot reliably determine the causes of present
attributes.

Answer choice (D): In the stimulus the author asserts that self-reported experiences are of
questionable reliability, rendering retrospective studies unreliable as well:

Self-reported info can NOT reliably determine past causes of present attributes

This incorrect answer choice presents something similar to a Mistaken Negation of that statement:

Accurate info can reliably determine past causes of present attributes

The author of the stimulus asserts that retrospective studies, based on self-reported information,
cannot reliably determine past causes of present characteristics. This is certainly not the same as
asserting that accurate information will guarantee reliable causal determinations.

Answer choice (E): The stimulus deals only with retrospective studies, and the author has already
established that such studies must rely on subjects’ reports of past experiences in determining the
causes of current attributes, so this choice does provide the link we seek between self-reported
information and a lack of reliability of that information.

[allisonellen7]

Hi there!
I am having trouble understanding why A couldn't be correct as well. Wouldn't you have to assume that whether the study is reliable must depend at least in part on the extent to which that study uses inaccurate reports about the subjects' pasts. It seems like if you negate this assumption, it goes against the conclusion. Whereas it seems like C could be assumed but the study could still be reliable even with the inaccurate reports..? Or is needing reliable reports something so obvious that you don't even have to state that it's an assumption? But if so, how do you determine what is too obvious and what is a needed assumption? Thank you for your help!

[Nikki Siclunov]

Hi,

I'm having trouble following your question. Question 9 from that passage is a Parallel Reasoning question, where answer choice (A) is correct: the schematic drawings accompanying an engineer’s oral presentation function in the same way as custom-made medical illustrations do when used alongside expert testimony. In both cases, the pictorial device helps “translate” technical terminology into visual imagery.

Perhaps you had a different question in mind?

Thanks!

[allisonellen7]

Thanks for your response but I think you may be looking at the wrong one! On this one I was wondering about the logical reasoning section from the December 2010 test. Thanks again!

[Andrew Ash]

Hi, Allison, good to hear from you again!

We found the question you were talking about (it's about retrospective studies, for those of you following along). Sorry for the confusion!

The key here is the question stem itself. It does contain the word "assumed," but be careful, it's actually a Justify! The Help family stems often look a lot like each other, so it's important to be able to tell them apart reliably. Take a look at page 4-18 from your Full Length Course books for a helpful discussion of how to identify a Justify stem.

You are perfectly correct that answer choice (A) is a necessary assumption of the argument, and that negating it destroys the argument. But we're looking for an answer that justifies the argument - that makes it completely, inescapably correct - and (A) doesn't do that. In fact, (A) doesn't make the argument stronger at all, because it doesn't say how inaccurate reports affect the reliability.

The argument in the stimulus is problematic because it jumps from the premise that these studies use subjects' reports about their own pasts to concluding that these studies are reliable. For a Justify question, we need a connecting element that demonstrates, beyond a shadow of a doubt, that these reports are somehow unreliable. Answer choice (C) asserts that these reports are "highly susceptible to inaccuracy," which closes the gap.

I hope that helps. Talk to you soon!

Best,
Andrew

[allisonellen7]

Oh my gosh yes that helps so much! That makes a lot of sense. Thank you so much!

[bk1111]

Hi, I got this question right but I am unable to confidently eliminate D. I ultimately eliminated it because D talks about what "can reliably determine" causes and the conclusion in the stimulus talks about what "cannot reliably determine" causes. Is this the correct reasoning behind eliminating this answer choice?

[Francis O'Rourke]

The difference you pointed out, between what can and cannot reliably determine the causes, is one part of what makes Choice (D) irrelevant to justifying the conclusion. Knowing what will make such a report reliable cannot help us justify why these reports are unreliable.

One other factor that should help us cross off choice (D) is that we do not know if the study used only accurate reports - i.e. the sufficient condition of choice (D). Since the sufficient condition is not proven, choice (D) does not provide any additional information.

[Esda08]

Hi, I got this question right but used the Mechanistic Approach. Would it be ok to use this approach? Since "significant connections between the present characteristics of subjects and what happened to those subjects in the past" wasn't in the conclusion and "subjects' reports about their own pasts" was in the conclusion, I decided these were items that had to be found in the correct answer choice. However, now that I look at the stimulus again I see that "subjects' reports about their own pasts" may actually be another premise. Thanks in advance for your help!

[Alex Bodaken]

Edsa08,

Thanks for the question! Applying a mechanistic lens to Justify questions is nearly always a good idea, even if it doesn't always get us all the way to the correct answer choice. As was stated earlier in this thread:

"Applying the Justify Formula, we can pinpoint the rogue elements that must be linked for the
conclusion to be properly drawn: The right answer will likely provide that studies which rely on
subjects to report on their past experiences cannot reliably determine the causes of participants’
present characteristics."

That being said, I agree with your assertion that the "subjects' reports about their own pasts" is actually found in both the stimulus and the conclusion. Therefore, the link we are looking for is something that tells us why the subjects' reports about their own past is not to be trusted - and that's what we find with answer choice (C). Whether that would be considered a mechanistic approach is I think up for debate, but it's clear that is the missing link, and therefore what we should be looking for as we head to the answer choices.

Hope that helps!
Alex