Criminals released from prison on parole

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Criminals released from prison on parole

by vivekvijayan » Mon Oct 27, 2014 12:08 am
Criminals released from prison on parole have generally been put under routine supervision. A recent program has allowed criminals to leave prison early under intensive supervision; they must obey curfews and in some cases they must be electronically monitored. The percentage of released criminals arrested while under supervision is the same for intensive supervision as for routine supervision, so intensive supervision is no more effective than routine supervision in preventing criminals from committing additional crimes.

Which one of the following is an assumption on which the argument relies?

(A) The criminals under intensive supervision, but not those under routine supervision, were required to work or attend school during their supervision period.

(B) All of the criminals who were arrested while under routine supervision had been in prison more than once before being paroled and put under supervision.

(C) The proportion of arrests to crimes committed was not significantly higher for criminals under intensive supervision than those under routine supervision.

(D) Of the criminals arrested while under intensive supervision, some would not have committed crimes if they had been under routine supervision.

(E) The number of criminals put under routine supervision was not significantly greater than the number of criminals put under intensive supervision.

OA C

I got the correct answer, but that was more by way of intuition than logic. Experts could you pls explain with perhaps an example how can C be the assumption here.

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by GMATGuruNY » Mon Oct 27, 2014 4:42 am
vivekvijayan wrote:Criminals released from prison on parole have generally been put under routine supervision. A recent program has allowed criminals to leave prison early under intensive supervision; they must obey curfews and in some cases they must be electronically monitored. The percentage of released criminals arrested while under supervision is the same for intensive supervision as for routine supervision, so intensive supervision is no more effective than routine supervision in preventing criminals from committing additional crimes.

Which one of the following is an assumption on which the argument relies?

(A) The criminals under intensive supervision, but not those under routine supervision, were required to work or attend school during their supervision period.

(B) All of the criminals who were arrested while under routine supervision had been in prison more than once before being paroled and put under supervision.

(C) The proportion of arrests to crimes committed was not significantly higher for criminals under intensive supervision than those under routine supervision.

(D) Of the criminals arrested while under intensive supervision, some would not have committed crimes if they had been under routine supervision.

(E) The number of criminals put under routine supervision was not significantly greater than the number of criminals put under intensive supervision.
This CR exhibits a LANGUAGE SHIFT:
Whereas the premise is about X, the conclusion is about Y.

Premise: The percentage of released criminals ARRESTED while under supervision is the same for intensive supervision as for routine supervision.
Conclusion: Intensive supervision is no more effective than routine supervision in preventing criminals from committing additional CRIMES.
Whereas the premise is about BEING ARRESTED, the conclusion is about COMMITTING CRIMES.

The assumption that there is a link between the number of arrests and the number of crimes.
Since the assumption is WHAT MUST BE TRUE, apply the NEGATION TEST.
When the correct answer choice is negated, the conclusion will be invalidated.
C, negated:
The proportion of arrests to crimes committed was significantly higher for criminals under intensive supervision than for those under routine supervision.
If criminals under intensive supervision were arrested 1 time for every 2 crimes committed (a ratio of 1/2), while criminals under routine supervision were arrested 1 time for every 10 crimes committed (a rate of 1/10), the criminals under intensive supervision committed FEWER CRIMES for each arrest, invalidating the conclusion that intensive supervision is no more effective than routine supervision in preventing criminals from committing additional CRIMES.
Since the negation of C invalidates the conclusion, C is the assumption: WHAT MUST BE TRUE for the conclusion to be valid.

The correct answer is C.
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by David@VeritasPrep » Mon Oct 27, 2014 10:21 am
You have found a great CR question from the Veritas Prep Advanced Verbal Lesson.

I understand why you may have some difficulty with this one as it is a difficult question.

However, it is also a question that follows a certain form that is quite common to the GMAT. That form is the "switch in terms."

You can notice the switch in terms if you focus closely on the evidence and on the conclusion. The evidence is about the percentage of criminals on parole who are "arrested" - that percentage is about the same for intensive and for routine supervision. Yet the conclusion switches terms to talk about "crimes committed" and claims that both types are equally good for preventing crimes from being committed.

When you spot this switch you most likely have either an assumption question or a weaken question. If it is an assumption question like this one you want to say that the two things are equally, thereby saving the argument. So you say that evidence about arrests is good for proving a conclusion about crimes committed. In other words you want arrests to translate to crimes committed. Choice C guarantees that translation.

If this is a weaken question then you will simply want to state that arrests are different from crimes committed. That is enough to weaken this argument.

As a bonus I want to tell you about the statistics on this question. From what I have observed from hundreds of students choice E is just about as popular as the correct answer C. Of course there is one word that makes E not the correct answer for this question. That word is "percentage" as in "The percentage of released criminals arrested while under supervision is the same..." percentages are already comparable and do not need to be adjusted or weighted. If the evidence had said "the NUMBER of criminals arrested" then you would want to go for choice E as we would a statistics problem.
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by Md Raihan Uddin » Tue Oct 28, 2014 8:51 am
David@VeritasPrep wrote:You have found a great CR question from the Veritas Prep Advanced Verbal Lesson.

As a bonus I want to tell you about the statistics on this question. From what I have observed from hundreds of students choice E is just about as popular as the correct answer C. Of course there is one word that makes E not the correct answer for this question. That word is "percentage" as in "The percentage of released criminals arrested while under supervision is the same..." percentages are already comparable and do not need to be adjusted or weighted. If the evidence had said "the NUMBER of criminals arrested" then you would want to go for choice E as we would a statistics problem.
Hi David,

I understand what you say. But E is ok to me because Premise says percentage for both is same. Please consider the following.

Routine- 10% of 100000 = 10000
Intensive- 10% of 100 = 10

This is what I thought when I was trying to answer the question. But now I can see that E actually has removed the possibility of such example. So it is a type of strengthener not the assumption. Because if above example is true and E eliminate that possibility, it can't shatter the conclusion.

Am I right? Please help me.

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by David@VeritasPrep » Wed Oct 29, 2014 5:48 am
No that is not correct.

"Percentage arrested is the same" is always comparable. So it does not matter if you have 10,000 people under routine supervision and 100 people under intensive supervision. What matters is at what rate these people are arrested.

So if the percentage arrested is 10% then 90% are not arrested and 10% are and that is always comparable. For example, if you got 90% of the points in your algebra class and I got 80% of the available points in my algebra class it does not matter how many points are available, you did better than I did.

Let me give you an example of when choice E would be correct. If we said that the same NUMBER of criminals were arrested under each - so for example 100 people are arrested under each program. Now you need to know how many people are in each program because 100 arrested out of 100 under intensive supervision is very different than 100 arrested out of 10,000 under normal supervision.

I have actually written an just published an entire article about percentage versus number. You can find it at https://www.businessweek.com/articles/20 ... n-the-gmat.
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by conquistador » Sun Nov 01, 2015 2:15 am
David@VeritasPrep wrote:No that is not correct.

"Percentage arrested is the same" is always comparable. So it does not matter if you have 10,000 people under routine supervision and 100 people under intensive supervision. What matters is at what rate these people are arrested.

So if the percentage arrested is 10% then 90% are not arrested and 10% are and that is always comparable. For example, if you got 90% of the points in your algebra class and I got 80% of the available points in my algebra class it does not matter how many points are available, you did better than I did.

Let me give you an example of when choice E would be correct. If we said that the same NUMBER of criminals were arrested under each - so for example 100 people are arrested under each program. Now you need to know how many people are in each program because 100 arrested out of 100 under intensive supervision is very different than 100 arrested out of 10,000 under normal supervision.

I have actually written an just published an entire article about percentage versus number. You can find it at https://www.businessweek.com/articles/20 ... n-the-gmat.
Hello David, I got E first and then rethought as below. Is my analysis correct? I have gone through the responses mentioned above and OE but still could not get how the concept of clever wordplay can lead us to the answer. Also I could not find the businessweek article written by you. PLease help.

Criminals released from prison on parole have generally been put under routine supervision.
A recent program has allowed criminals to leave prison early under intensive supervision;
they must obey curfews and in some cases they must be electronically monitored.
The percentage of released criminals arrested while under supervision is the same for intensive supervision as for routine supervision,
Conclusion: [highlight]so intensive supervision is no more effective than routine supervision in preventing criminals from committing additional crimes.[/highlight]

those on parole cannot be more than the people on routine supervision.
but % of criminals who got caught is same for both categories.
more people on intensive supervision may have got caught.

Which one of the following is an assumption on which the argument relies?

(A) The criminals under intensive supervision, but not those under routine supervision, were required to work or attend school during their supervision period..............OUT of scope
(B) All of the criminals who were arrested while under routine supervision had been in prison more than once before being paroled and put under supervision................This does not help us much. Although not really sure why it doesn't.
(D) Of the criminals arrested while under intensive supervision, some would not have committed crimes if they had been under routine supervision.
so this means hat they committed crimes only because they are under intensive supervision i.e., intensive encourages them to commit more crimes i.e., it is worse rather than being more effective. Negates the conclusion.

Well I got stuck between C and E.

(E) The number of criminals put under routine supervision was not significantly greater than the number of criminals put under intensive supervision.
This cant be true as you don't release almost half of the inmates on parole.

(C) The proportion of arrests to crimes committed was not significantly higher for criminals under intensive supervision than those under routine supervision.
Well I chose E at first but this came out to be the assumption when the test of negation is applied.
negated C: The proportion of arrests to crimes committed was significantly higher for criminals under intensive supervision than those under routine supervision.
i.e., more crimes under intensive supervision same as D thereby collapsing the argument.
So This is an assumption.