PTF97.S3.Q20 - Criminals released from prison on parole..

alvaroescobedo

Can someone explain why AC C is right and E is wrong.

Option C states that "the proportion of arrests to crimes committed was not significantly higher for criminals under intensive supervision than for those under routine supervision." This statement is not an assumption on which the argument relies. Instead, it is a piece of evidence presented in the argument to support the conclusion that intensive supervision is no more effective than routine supervision in preventing criminals from committing additional crimes. The argument states that the percentage of released criminals arrested while under supervision is the same for intensive supervision as for routine supervision, and cites the fact that the proportion of arrests to crimes committed was not significantly higher for criminals under intensive supervision as evidence for this claim. However, this statement does not itself form the basis for the argument's conclusion.

Option E is an assumption on which the argument relies. The argument states that the percentage of released criminals arrested while under supervision is the same for intensive supervision as for routine supervision, and concludes that intensive supervision is no more effective than routine supervision in preventing criminals from committing additional crimes. However, this conclusion relies on the assumption that the number of criminals put under routine supervision was not significantly greater than the number of criminals put under intensive supervision. If the number of criminals put under routine supervision was significantly greater, it could be that the percentage of released criminals arrested while under supervision is the same simply because there are more criminals under routine supervision. In that case, it would not be accurate to conclude that intensive supervision is no more effective than routine supervision

azlawgirl

Im not positive but I think this is why - If you negate answer choice C "the proportion of arrests to crimes committed WAS significantly higher for criminals under intensive supervision than for those under routine supervision." this completely wrecks the conclusion because the metric your measuring against is no longer equal (aka more people can get away with a crime and not be arrested so we no longer have the information to say which is more effective because we dont have accurate data), alternatively if you negate E "the number of criminals put under routine supervision WAS significantly greater than the number of criminals put under intensive supervision" that does not immediately wreck the conclusion because the conclusion is based on a percentage of the total for each type, so just because the total number of routine supervision criminals was higher we cant assume more people were arrested because we dont have that information, therefore it isnt necessary. The two groups don't have to be equal in number of criminals because the conclusion is based on a percentage

sprsplspig

Hi! This is pretty late but here's my understanding of this question:

Translation:
1. Usually, criminals released from prison have routine supervision [ok, they're about to say something contrary to what happens "usually"]
2. now, there's this new program that allows some prisoners to be released early under intense supervision -- they hv curfews and maybe even electronically monitored [woah ok, so we know some released prisoners are subject to super intense supervision]
3. percentage of released criminals arrested under intense and regular supervision is the same [ok so it seems like prisoners released who misbehave may get arrested again. and we know that percentage of those re-arrested for intense and regular supervision are the same...this is heading towards a conclusion]

conclusion: intense supervision not better at preventing released criminals from committing additional crimes

woah hold on, so they are rly using a premise about the percentage of ARRESTS to make a conclusion about crime PREVENTION? What is this reasoning? The author must make some kind of assumption that the percentage of arrests = percentage of crimes committed.

Isn't it likely that it is precisely because intense supervision is SO intense, that no one gets away with the crimes they committed -- hence they all get arrested. like, if you are electronically tracking my location every second, ofc you're gonna catch me when I commit a crime.

on the other hand, maybe routine supervision just fails to catch all the crimes --> hence less arrests. If this were true, it could totally be the case that almost ALL of the criminals released under "routine supervision" are committing crimes, but they are just not getting arrested bc the routine supervision fails to supervise them.

Ok, now to the answer choices
Negate E: number of criminals released under routine was much greater than the number released under intensive.
The reason E is wrong is because differences in number of prisoners released is accounted for by the stimulus. We know the proportion of arrests are the same, regardless of how many prisoners were released under each type of supervision.

E.g. 10 criminals are released under routine, 2 criminals released under intensive.

but the percentage of arrests are the same. Suppose the percentage is 50%, then 5 are arrested under routine, 1 is arrested under intensive. So here, even though many more criminals are released under routine supervision, as long as the percentage of arrests are the same, the conclusion still holds. For E to be correct, the conclusion would've had to say: "so intensive supervision is not better at arresting less number of released criminals."

C is correct because it attacks the gap in the argument that jumps from percentage of arrests to percentage of crimes committed. If we negate C, it is not the case that intense supervision failed to prevent crimes, but that its making many more arrests, relative to the crimes committed.

dpgold24

Adding my reasoning in as well! I mainly got stuck between AC C & D.

Pre-phrase/key assumption made is about prevention. Just bc both supervision programs have the same % of people arrested again doesn't indicate how effective the supervision is at prevention. We don't know how many people from each groups attempted crimes (FWIW it seems like good counterargument that almost 100% of crimes attempted in the intense supervision group would be arrested, as opposed to less in the routine group bc of the nature of the supervision).

A: irrelevant
B: irrelevant
C: Yes - this shows that the % can be trusted and used to draw the conclusion that the author draws, it is a blocking NA bc blocks it from the point above about the difference in supervision. If this AC was negated, it would show that you cannot use the % to draw this conclusion bc it would show there are MORE crimes in the routine group meaning it did not do the same at PREVENTION as the intense supervision group did.
D) This AC trapped me for a while bc if it was flips the types of supervision, I think it would be an NA. The way I was ultimately able to eliminate this was by negating, it would actually strengthen the arg. as opposed to wrecking it.
E) this would not impact the argument bc the support comes from a percentage and not a raw number. the % would stay the same regardless of the raw numbers.