A large group of hyperactive children whose regular diets included foo

Question

A large group of hyperactive children whose regular diets included food containing large amounts of additives was observed by researchers trained to assess the presence or absence of behavior problems. The children were then placed on a low-additive diet for several weeks, after which they were observed again. Originally nearly 60 percent of the children exhibited behavior problems; after the change in diet, only 30 percent did so. On the basis of these data, it can be concluded that food additives can contribute to behavior problems in hyperactive children.

The evidence cited fails to establish the conclusion because

(A) there is no evidence that the reduction in behavior problems was proportionate to the reduction in food-additive intake

(B) there is no way to know what changes would have occurred without the change of diet, since only children who changed to a low-additive diet were studied

(C) exactly how many children exhibited behavior problems after the change in diet cannot be determined, since the size of the group studied is not precisely given

(D) there is no evidence that the behavior of some of the children was unaffected by additives

(E) the evidence is consistent with the claim that some children exhibit more frequent behavior problems after being on the low-additive diet than they had exhibited when first observed

push12345 · Accepted Answer

Conclusion -food additives can contribute to behavior problems in hyperactive children.

We need to weaken the above conclusion

During the experiment only changes are observed when changing diet

But What about changes being observed when no diet is changed.is it consistent with experiment result or not

Without this information we cannot say conclusion is correct or not

B correctly states this

Give kudos if it helps

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Bunuel · Answer

OFFICIAL EXPLANATION

(A) No. The evidence fails to even establish that it was the reduction in food-additive intake which caused the reduction in behavior problems, let alone that it caused a proportionate reduction.

(B) Yes.  In order for the conclusion to reasonably follow, we need to know what would have happened had the diet not been changed. Perhaps the same decrease in behavior problems would have occurred even if the diet was not changed. In other words, we need a control group with which to compare the results of the test group.

(C) No. In this situation, percentage is more important than absolute number.

(D) No. This is irrelevant.

(E) No. Since the evidence fails to establish anything, this answer-choice is not incorrect. However, there is a more precise answer-choice.

Abhishek009 · Answer

(A) Proportionate comparison is incorrect.
(B) True, the entire population was studied a control group was not taken as such we can not be certain about the results/observations.
(C) Number of children is not the concern here.
(D) Out of scope.
(E) Frequency of Behaviour problem - Not discussed, hence out of context.

Correct Answer must be (B)

mgcon · Answer

This question reminds me of every argument that I have with my boss regarding the effectiveness of a campaign or strategy by looking at absolute numbers & not considering a control group :D

mrinali · Answer

(A) there is no evidence that the reduction in behavior problems was proportionate to the reduction in food-additive intake -----  We just need an answer in yes/no terms whether the reduction in behavior problems was caused by reduction in food-additive intake and do no need to know the degree of reduction. Hence out of scope.

(B) there is no way to know what changes would have occurred without the change of diet, since only children who changed to a low-additive diet were studied -----  Correct. It may be possible that a reduction in behavior problems was observed in even in children who still continued the same diet. to arrive at the the desired conclusion, we need to rule out this possibility.

(C) exactly how many children exhibited behavior problems after the change in diet cannot be determined, since the size of the group studied is not precisely given -----  We do not need a precise number as we already have the percentage of the children in question

(D) there is no evidence that the behavior of some of the children was unaffected by additives ---- Out of scope. We just need to establish that a low-additives diet leads to a reduction in behavior problems in children

(E) the evidence is consistent with the claim that some children exhibit more frequent behavior problems after being on the low-additive diet than they had exhibited when first observed----  No such claims have been made in the data.

unraveled · Answer

A large group of hyperactive children whose regular diets included food containing large amounts of additives was observed by researchers trained to assess the presence or absence of behavior problems. The children were then placed on a low-additive diet for several weeks, after which they were observed again. Originally nearly 60 percent of the children exhibited behavior problems; after the change in diet, only 30 percent did so. On the basis of these data, it can be concluded that food additives can contribute to behavior problems in hyperactive children.

The evidence cited fails to establish the conclusion because

(A) there is no evidence that the reduction in behavior problems was  proportionate to the reduction  in food-additive intake - WRONG. 'Proportionality' ruins this option. Otherwise it was good.

(B) there is no way to know what changes would have occurred without the change of diet, since only children who changed to a low-additive diet were studied - CORRECT. Not 100% sure how this is right but it is. Hopefully the large group remained unchanged so this option confuses. Alternate cause is what i was looking for but none of the options offer that.

(C)  exactly how many children exhibited behavior problems  after the change in diet cannot be determined, since the size of the group studied is not precisely given - WRONG. Knowing the number would not have helped us anyhow.

(D) there is no evidence that the  behavior of some of the children was unaffected  by additives - WRONG. Yes, that's what passage also suggests. So nothing wrong as such in that.

(E) the evidence is  consistent with the claim  that some children exhibit more frequent behavior problems after being on the low-additive diet than they had exhibited when first observed - WRONG. If it's consistent then how can it be flawed.

Answer A.

agrasan · Answer

The author concluded:
Change in diet from high additive to low additive --> Reduction in children exhibiting behavior problems

(A) there is no evidence that the reduction in behavior problems was proportionate to the reduction in food-additive intake
 This is  not a flaw , when we say a proportional relationship between two variables, we mean that the ratio is constant but the author never mentioned that for 20% reduction in additive diet, we will see 30% reduction in children exhibiting behavior problems.

(B) there is no way to know what changes would have occurred without the change of diet, since only children who changed to a low-additive diet were studied
  Flaw ,   correlation causation   is a major problem with this argument. We are just given that we changed the diet from high additive to low additive and saw a reduction in behavior problems but we don't know whether it was change in diet or something else that caused this. If we had children from high additive diet as well, then we would have got a better idea whether diet changes lead to behavior problem reduction or not.

(C) exactly how many children exhibited behavior problems after the change in diet cannot be determined, since the size of the group studied is not precisely given
 This is  not a flaw , we are not worried about the number of children, we want to what's the fundamental problem in author's conclusion that change in diet leads to change in children exhibiting behavior problems.

(D) there is no evidence that the behavior of some of the children was unaffected by additives
 This is  not a flaw , some children who were unaffected by additives doesn't change the fact that 30% of children were affected by the change in diet.

(E) the evidence is consistent with the claim that some children exhibit more frequent behavior problems after being on the low-additive diet than they had exhibited when first observed
 This is  not a flaw , the study gave  average results  so it is expected that few can be outliers.

A large group of hyperactive children whose regular diets included foo

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A large group of hyperactive children whose regular diets included foo

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