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# A recent study of college students shows that, contrary to

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A recent study of college students shows that, contrary to [#permalink]

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06 Jul 2008, 18:16
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A recent study of college students shows that, contrary to predicted results, special nutritional planning does not positively affect students’ grades. Sixty students, half of whom were given a nutritionally balanced diet, had grades no higher than did those students who were not placed on the diet plan.

Which of the following, if true, is most useful in determining the accuracy of the study described above?

(A) Performance of business executives was shown to improve drastically after major alterations were made in their diets.
(B) Honors students, after altering their diets, maintained that they did not change their study habits.
(C) Students who participated in various fitness regimens found that their grades improved appreciably after they altered their exercise habits.
(D) High school students who previously had low grades found that after they altered their diets, their grades improved dramatically.
(E) All of the college students who volunteered for the study were either in their first or second year of college.

I marked the answer at ii), because if no changes were made to the study habits then we can conclude that there was no effect of study habits on the study, hence effect of diet can be correctly determined (Whether it had some effect or not). But this answer is wrong . Can anybody explain the correct answer).
[Reveal] Spoiler: OA
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06 Jul 2008, 18:25
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contrary to predicted results, special nutritional planning does not positively affect students’ grades

Predicted results would have been special nutritional planning positively affect students’ grades

C & E are out of scope

Among A, B and D

A is using business executive performance improvement. We don't know whether we can relate real time performance improvement to grades (ironically like GMAT and real time) Still I would hold it for now

I agree with your reasoning on B but we simply don't know whether it had any effect or not. But it sounds as if diet did not had any effect Also, we are talking about a subset of students

D is saying low grade HS students with the new diet improved their grades

Look at the Q again.

Which of the following, if true, is most useful in determining the accuracy of the study described above?

D stands on the expected side of results. Probably study is wrong or this case of college students is an anomaly

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07 Jul 2008, 06:09
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Which of the following, if true, is most useful in determining the accuracy of the study described above?

We are only concerned about the accuracy of the study. The study looked at 60 students. If these 60 students were not a random group then the study would not be accurate. For example half the students could be seniors who tend to get steady grades because they have made it to their senior year and the other half could be freshmen whose grades are all over the place.

v) All of the college students who volunteered for the study were either in their first or second year of college.

This is the only answer that adds to the validity of the study sample.
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07 Jul 2008, 06:22
A recent study of college students shows that, contrary to predicted results, special nutritional planning does not positively affect students’ grades. Sixty students, half of whom were given a nutritionally balanced diet, had grades no higher than did those students who were not placed on the diet plan.

Which of the following, if true, is most useful in determining the accuracy of the study described above?

i) Performance of business executives was shown to improve drastically after major alterations were made in their diets. irrelevant
ii)Honors students, after altering their diets, maintained that they did not change their study habits. Not talking about study habits.Also, Unchanged study habits may not guarantee same high grades.
iii)Students who participated in various fitness regimens found that their grades improved appreciably after they altered their exercise habits. irrelevant
iv) High school students who previously had low grades found that after they altered their diets, their grades improved dramatically. tells us precisely whether argument's conclusion is accurate or not.
v) All of the college students who volunteered for the study were either in their first or second year of college.
irrelevant

IMO D
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07 Jul 2008, 06:31
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chan4312 wrote:
A recent study of college students shows that, contrary to predicted results, special nutritional planning does not positively affect students’ grades. Sixty students, half of whom were given a nutritionally balanced diet, had grades no higher than did those students who were not placed on the diet plan.

Which of the following, if true, is most useful in determining the accuracy of the study described above?

i) Performance of business executives was shown to improve drastically after major alterations were made in their diets. irrelevant
ii)Honors students, after altering their diets, maintained that they did not change their study habits. Not talking about study habits.Also, Unchanged study habits may not guarantee same high grades.
iii)Students who participated in various fitness regimens found that their grades improved appreciably after they altered their exercise habits. irrelevant
iv) High school students who previously had low grades found that after they altered their diets, their grades improved dramatically. tells us precisely whether argument's conclusion is accurate or not.
v) All of the college students who volunteered for the study were either in their first or second year of college.
irrelevant

IMO D

How does that affect the accuracy of this test?

If I do a test of college students. And I ask you to comment on the accuracy of my test on college students and you tell me you did a test on high school students and got different results. How does that affect the ACCURACY of my test? Wouldn't you have to focus on my methods to comment on the accuracy of my test?

To me we are only concerned with the accuracy of the study and not the results.
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07 Jul 2008, 07:08
gixxer1000 wrote:
chan4312 wrote:
A recent study of college students shows that, contrary to predicted results, special nutritional planning does not positively affect students’ grades. Sixty students, half of whom were given a nutritionally balanced diet, had grades no higher than did those students who were not placed on the diet plan.

Which of the following, if true, is most useful in determining the accuracy of the study described above?

i) Performance of business executives was shown to improve drastically after major alterations were made in their diets. irrelevant
ii)Honors students, after altering their diets, maintained that they did not change their study habits. Not talking about study habits.Also, Unchanged study habits may not guarantee same high grades.
iii)Students who participated in various fitness regimens found that their grades improved appreciably after they altered their exercise habits. irrelevant
iv) High school students who previously had low grades found that after they altered their diets, their grades improved dramatically. tells us precisely whether argument's conclusion is accurate or not.
v) All of the college students who volunteered for the study were either in their first or second year of college.
irrelevant

IMO D

How does that affect the accuracy of this test?

If I do a test of college students. And I ask you to comment on the accuracy of my test on college students and you tell me you did a test on high school students and got different results. How does that affect the ACCURACY of my test? Wouldn't you have to focus on my methods to comment on the accuracy of my test?

To me we are only concerned with the accuracy of the study and not the results.

I can not agree with you.
we are talking about how students respond to planned special nutritional diet.
Does it matter if the student is a college student or high scholl student.whether student is 15 year old or 35 year old. unless people respond differently for the same diet.argument does not say so..so we can not predict. I do not think it matters. our input is diet and our output is grades. if this holds true/false determines whether study is accurate/inaccurate.
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07 Jul 2008, 07:19
chan4312 wrote:
gixxer1000 wrote:
chan4312 wrote:
A recent study of college students shows that, contrary to predicted results, special nutritional planning does not positively affect students’ grades. Sixty students, half of whom were given a nutritionally balanced diet, had grades no higher than did those students who were not placed on the diet plan.

Which of the following, if true, is most useful in determining the accuracy of the study described above?

i) Performance of business executives was shown to improve drastically after major alterations were made in their diets. irrelevant
ii)Honors students, after altering their diets, maintained that they did not change their study habits. Not talking about study habits.Also, Unchanged study habits may not guarantee same high grades.
iii)Students who participated in various fitness regimens found that their grades improved appreciably after they altered their exercise habits. irrelevant
iv) High school students who previously had low grades found that after they altered their diets, their grades improved dramatically. tells us precisely whether argument's conclusion is accurate or not.
v) All of the college students who volunteered for the study were either in their first or second year of college.
irrelevant

IMO D

How does that affect the accuracy of this test?

If I do a test of college students. And I ask you to comment on the accuracy of my test on college students and you tell me you did a test on high school students and got different results. How does that affect the ACCURACY of my test? Wouldn't you have to focus on my methods to comment on the accuracy of my test?

To me we are only concerned with the accuracy of the study and not the results.

I can not agree with you.
we are talking about how students respond to planned special nutritional diet.
Does it matter if the student is a college student or high scholl student.whether student is 15 year old or 35 year old. unless people respond differently for the same diet.argument does not say so..so we can not predict. I do not think it matters. our input is diet and our output is grades. if this holds true/false determines whether study is accurate/inaccurate.

We are talking about how sixty college students respond to a planned special nutrition diet. We need information to help determine the accuracy of the study. Contradicting results from another study does not affect the accuracy of this studies results. We are looking for answers that shows that the sixty college students chosen are a good or bad sample. Or some other reason to show that the study was accurate or inaccurate.
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07 Jul 2008, 08:35
It's a tough fight between A and D for me.
Since Conclusion is not a generic statement that diets help in performance but specific to students, I am more inclined to opt for D.

E is clearly out, it really does not matter who took the test as long as they were students. Facts clearly mention that it is just students who took the test.
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07 Jul 2008, 08:49
Ashwin_Mohan wrote:
It's a tough fight between A and D for me.
Since Conclusion is not a generic statement that diets help in performance but specific to students, I am more inclined to opt for D.

E is clearly out, it really does not matter who took the test as long as they were students. Facts clearly mention that it is just students who took the test.

So if you chose 30 college seniors with straignt A's and 30 college freshmen with all D's that wouldn't affect the ACCURACY of the test results.

I fail to see how outside test results affect the accuracy this test results. Can someone explain?
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07 Jul 2008, 08:50
gixxer1000,

If you look at the Q again, it does not say how does it effect the accuracy of the test?

It says which one will be most helpful in determining the accuracy of the test?
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07 Jul 2008, 09:38
icandy wrote:
gixxer1000,

If you look at the Q again, it does not say how does it effect the accuracy of the test?

It says which one will be most helpful in determining the accuracy of the test?

I understand that. We need to choose the answer that most helps us determine if the test is or is not accurate. So to determine if the test is accurate we need to look at the methods of the test. How it was conducted, who was tested, etc. A, B, C, and D all deal with factors other than the test in question. How would these outside factors help us to determine the accuracy of this test.
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07 Jul 2008, 09:54
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bhatiasanjay01 wrote:
A recent study of college students shows that, contrary to predicted results, special nutritional planning does not positively affect students’ grades. Sixty students, half of whom were given a nutritionally balanced diet, had grades no higher than did those students who were not placed on the diet plan.

Which of the following, if true, is most useful in determining the accuracy of the study described above?

i) Performance of business executives was shown to improve drastically after major alterations were made in their diets.
ii)Honors students, after altering their diets, maintained that they did not change their study habits.
iii)Students who participated in various fitness regimens found that their grades improved appreciably after they altered their exercise habits.
iv) High school students who previously had low grades found that after they altered their diets, their grades improved dramatically.
v) All of the college students who volunteered for the study were either in their first or second year of college.

I marked the answer at ii), because if no changes were made to the study habits then we can conclude that there was no effect of study habits on the study, hence effect of diet can be correctly determined (Whether it had some effect or not). But this answer is wrong . Can anybody explain the correct answer).

Conclusion: special nutritional planning does not positively affect students’ grades.
Evidence:Sixty students, half of whom were given a nutritionally balanced diet, had grades no higher than did those students who were not placed on the diet plan.

The evidence here is weak becuase it provides no details about the student's grade before and after the intake of special diet.Only D brings in information to say students with previously lower grades performed well after they started takin in special diet and refute the conclusion that special diet donot affect student's growth. This answer choice can used to measure the accuracy of this conclusion made in the argument.

D
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07 Jul 2008, 09:58
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Interesting question.

bhatiasanjay01 wrote:
A recent study of college students shows that, contrary to predicted results, special nutritional planning does not positively affect students’ grades. Sixty students, half of whom were given a nutritionally balanced diet, had grades no higher than did those students who were not placed on the diet plan.

In blue, I've highlighted the conclusion that is drawn. Is this conclusion part of the study? We don't know. In any case, it's a strange conclusion: from a study of only college students, the writer concludes that nutrition "does not positively affect students’ grades" in general. If you wanted to weaken the conclusion, answer D is a clear choice:

bhatiasanjay01 wrote:
iv) High school students who previously had low grades found that after they altered their diets, their grades improved dramatically.

But weakening the conclusion is not what we're asked to do. The question is:

bhatiasanjay01 wrote:
Which of the following, if true, is most useful in determining the accuracy of the study described above?

I highlighted the part of the stem that refers to the study in red. We're asked to assess the accuracy of the study itself, not the conclusion. We can ignore what I've highlighted in blue. The only answer that refers to the methodology of the study (research methods, population that was studied, etc), is E:

bhatiasanjay01 wrote:
v) All of the college students who volunteered for the study were either in their first or second year of college.

Those studied were volunteers- the sample isn't random- and they were from a particular subset of the overall population. This could affect the vailidity of the study; a properly conducted study might reveal different results. So I agree with gixxer here; the correct answer should be E.
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Last edited by IanStewart on 07 Jul 2008, 09:59, edited 1 time in total.
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07 Jul 2008, 09:58
gixxer1000 wrote:
icandy wrote:
gixxer1000,

If you look at the Q again, it does not say how does it effect the accuracy of the test?

It says which one will be most helpful in determining the accuracy of the test?

I understand that. We need to choose the answer that most helps us determine if the test is or is not accurate. So to determine if the test is accurate we need to look at the methods of the test. How it was conducted, who was tested, etc. A, B, C, and D all deal with factors other than the test in question. How would these outside factors help us to determine the accuracy of this test.

Conclusion: special nutritional planning does not positively affect students’ grades.
Evidence:Sixty students, half of whom were given a nutritionally balanced diet, had grades no higher than did those students who were not placed on the diet plan.

The evidence here is weak becuase it provides no details about the student's grade before and after the intake of special diet.Only D brings in information to say students with previously lower grades performed well after they started takin in special diet and refute the conclusion that special diet donot affect student's growth. This answer choice can used to measure the accuracy of this conclusion made in the argument.
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07 Jul 2008, 10:03
bhatiasanjay01 wrote:
A recent study of college students shows that, contrary to predicted results, special nutritional planning does not positively affect students’ grades. Sixty students, half of whom were given a nutritionally balanced diet, had grades no higher than did those students who were not placed on the diet plan.

Which of the following, if true, is most useful in determining the accuracy of the study described above?

i) Performance of business executives was shown to improve drastically after major alterations were made in their diets.
ii)Honors students, after altering their diets, maintained that they did not change their study habits.
iii)Students who participated in various fitness regimens found that their grades improved appreciably after they altered their exercise habits.
iv) High school students who previously had low grades found that after they altered their diets, their grades improved dramatically.
v) All of the college students who volunteered for the study were either in their first or second year of college.

I marked the answer at ii), because if no changes were made to the study habits then we can conclude that there was no effect of study habits on the study, hence effect of diet can be correctly determined (Whether it had some effect or not). But this answer is wrong . Can anybody explain the correct answer).

Option E points towards the homogeneity of the sample.

E for me too.

However I feel such a survey cannot be conclusive. A better prepared survey would measure the performance of the same student over time.. when he is on an ordinary diet vs when he is on a planned nutritional diet.
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07 Jul 2008, 10:19
goalsnr wrote:
The evidence here is weak becuase it provides no details about the student's grade before and after the intake of special diet.Only D brings in information to say students with previously lower grades performed well after they started takin in special diet and refute the conclusion that special diet donot affect student's growth. This answer choice can used to measure the accuracy of this conclusion made in the argument.

We're not trying to measure the accuracy of the conclusion. The question is looking for the answer that helps us determine the accuracy of the study.

You could perform a test and draw an incorrect conclusion. The fact that the conclusion you draw is incorrect has nothing to do with the validity of the testing methods.

'Which of the following, if true, is most useful in determining the accuracy of the study described above?'
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07 Jul 2008, 14:04
gixxer1000 wrote:
goalsnr wrote:
The evidence here is weak becuase it provides no details about the student's grade before and after the intake of special diet.Only D brings in information to say students with previously lower grades performed well after they started takin in special diet and refute the conclusion that special diet donot affect student's growth. This answer choice can used to measure the accuracy of this conclusion made in the argument.

We're not trying to measure the accuracy of the conclusion. The question is looking for the answer that helps us determine the accuracy of the study.

You could perform a test and draw an incorrect conclusion. The fact that the conclusion you draw is incorrect has nothing to do with the validity of the testing methods.

'Which of the following, if true, is most useful in determining the accuracy of the study described above?'

Sorry Iam not a native English apeaker.So to me measure the accuracy and determine the accuracy mean the same. Now substitute that in my logic.The rest remains teh same. Hope thi shelps.
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08 Jul 2008, 06:47
@bhatiasanjay01

what is the OA and the Source ?
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28 Jul 2010, 05:22
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Even I wonder how it can be D. D says they altered the diet. It doesn't say they went on balanced diet which showed positive grade improvement.

B supports the study pattern. I can agrue that students changed study habit when they went on this nutricitional program and hence no grade imrovement.
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28 Jul 2010, 06:49
These are the kind of questions that make me hate multiple guess exams.

None of the choices are good. I choose F.

F) The control group (no special diet) had higher average grades before the study was conducted.
Re: CR: Nutrition Study   [#permalink] 28 Jul 2010, 06:49

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