Presentiment is said to be a phenomenon characterized by a person’s bodily functions, such as heart rate, shifting into response mode before a stressful event actually occurs. To determine whether presentiment is a real phenomenon, a group of researchers reviewed all of the studies of presentiment the results of which were published during the previous fifty years. Since the researchers found that the vast majority of the studies that they reviewed provided statistical evidence confirming that presentiment is a real phenomenon, they concluded that it is a real phenomenon.
Which of the following, if true, most seriously undermines the researchers’ conclusion?
The results of the studies that indicated that presentiment is a real phenomenon did not all show that it is with the same statistical significance.
People serving as subjects in studies of parapsychological phenomena such as presentiment are often compensated for their participation.
The people studied who appeared to be experiencing presentiment often were not fully aware that they were, though monitoring equipment reported changes in bodily functions.
The methods used in most of the studies reviewed were rigorous enough that the results that they generated could be considered reliable.
When, in the process of studying a phenomenon, researchers get unexciting results, they often forgo publishing their findings.
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Text Solution:
Breakdown of the Argument:
Background: Presentiment is said to be a phenomenon characterized by a person’s body functions shifting into response mode before a stressful event actually occurs.
Background: A group of researchers reviewed all of the studies of presentiment the results of which were published during the previous fifty years .
Premise: The vast majority of the studies that the researchers reviewed provided statistical evidence confirming that presentiment is a real phenomenon.
Conclusion: The researchers concluded that presentiment is a real phenomenon.
We need to weaken the support for the conclusion, which is based on study results.
One key detail to notice is that the argument mentions that the results considered had been “published.” How could this detail be important?
(A) The results of the studies that indicated that presentiment is a real phenomenon did not all show that it is with the same statistical significance.
Notice that this answer choice doesn’t say that the statistical significance of any study’s results was low. It just says that the statistical significance was not the same in all cases.
The fact that the statistical significance of results was not the same in all cases does not mean that the results were not solid evidence for the conclusion that presentiment is real.
So, what this choice says has no effect on the strength of the argument.
(B) People serving as subjects in studies of parapsychological phenomena such as presentiment are often compensated for their participation.
This answer choice could be taken as indicating that the participants in the studies mentioned could have been influenced by compensation to do things to make presentiment seem to be real even if it is not.
The truth is, however, that we don’t have any clear reason to believe that compensation influenced the study participants in that way. In fact, for all we know, the compensation influenced the study participants to do their best to generate accurate results.
Furthermore, we have no clear reason to believe even that the participants had the ability to affect the study results.
So, there is no clear path via which this choice would weaken the argument.
When answering Weaken questions, we must be careful to not choose as correct answer choices that state facts that seem significant yet do not weaken the argument.
(C) The people studied who appeared to be experiencing presentiment often were not fully aware that they were, though monitoring equipment reported changes in bodily functions.
Regardless of whether the people studied were aware that they were experiencing changes in bodily functions that appeared to constitute presentiment, they were experiencing those changes. Therefore, what this choice says does not affect the validity of the study results or affect the researchers’ conclusion based on the study results.
(D) The methods used in most of the studies reviewed were rigorous enough that the results that they generated could be considered reliable.
Since what this choice says serves to confirm the reliability of the study results upon which the researchers’ conclusion is based, it strengthens, rather than weakens, the support for the researchers’ conclusion.
CORRECT ANSWER(E) When, in the process of studying a phenomenon, researchers get unexciting results, they often forgo publishing their findings.
It is likely that study results that indicate that presentiment is not a real phenomenon would be considered unexciting.
Therefore, by saying that, when researchers studying a phenomenon get unexciting results, they often forgo publishing their findings, this choice provides a reason to believe that any researchers whose study results indicated that presentiment is not a real phenomenon may have decided not to bother publishing their results.
Thus, we can see that the set of published studies upon which the group of researchers’ conclusion is based may not have included some studies the results of which indicated that presentiment is not a real phenomenon. In other words, what this choice says indicates that the set of studies the group of researchers reviewed may have been a biased sample of studies of presentiment.
Thus, by indicating that the group of researchers may have based their conclusion on a sample that was biased in a way such that it would indicate that presentiment is a real phenomenon even if it isn’t real, this answer choice undermines the credibility of their conclusion.
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