Understanding the argument -
Criminals released from prison on parole have generally been put under routine supervision. - Background Info.
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. - Background Info.
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. - Meaning 10 out of 100 intensive (10%) supervision criminals are arrested, which is the same as, say, 100 out of 1000 (10%) under regular supervision. In conclusion, if the percentage of arrests is the same, intensive supervision is no more effective than routine supervision in preventing criminals from committing additional crimes. - The conclusion is about crimes. What if,
say - 10 crimes were committed in the intensive supervision case, and all 10 were arrested? While in the routine supervision case, 900 crimes were committed, but only 100 were arrested. Isn't intensive supervision more effective? Absolutely.
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. - the criminal history is out of scope.
(C) The proportion of arrests to crimes committed was not significantly higher for criminals under intensive supervision than those under routine supervision. - ok. Negation will shatter the conclusion.
(D) Of the criminals arrested while under intensive supervision, some would not have committed crimes if they had been under routine supervision. - hypothetical scenario. out of scope.
(E) The number of criminals put under routine supervision was not significantly greater than the number of criminals put under intensive supervision.- Irrelevant as we are comparing the percentages between the two in the argument.