PrepTest 159, Section 3, Question 12
When the annual period of daylight saving time(55 more words not shown)
Which one of the following,(6 more words not shown)
- AMany people forget(22 more words not shown)
- BTraffic accidents are(20 more words not shown)
- CThe traffic accidents(16 more words not shown)
- DThe higher incidence(17 more words not shown)
- EThe effects of(7 more words not shown)
Reading the argument
This sounds plausible. If the clocks move forward but you still have to get up for work at the usual time, you may lose an hour of sleep. Tired people having more accidents the next day makes sense.
Could something else explain the increase? Possibly. But I don't have a clear alternative in mind yet, and I don't want to invent a confident objection just because this is an argument. The author also says sleep deprivation is “likely” responsible, not that the evidence proves it beyond doubt.
What we’re looking for
For a strengthen question, I might look for reassurance that the comparison accounts for other relevant factors. That's a tentative guess. We'll need to read the answers and ask which one makes the sleep-deprivation explanation more convincing.
Working the answers
- A
Forgetting to change a clock can make someone late, but lateness isn't the same as sleep deprivation. In fact, rushing to an appointment could be a different explanation for accidents after the time change. A doesn't connect the increase in accidents specifically to lost sleep.
- B
The comparison is already with the average for that time of year. It isn't between the day after the clock change and a winter day. A broad seasonal difference therefore doesn't supply new support for the proposed explanation of this particular spike.
- C
We're explaining how often accidents happen, not how severe they are. The extra accidents could be minor or serious, and we'd still need to determine whether lost sleep is responsible for their increased frequency.
- DCorrect
This adds a useful pattern within the day: the extra accidents are most pronounced when sleep-deprived people tend to be most drowsy. That is what we'd expect if their lack of sleep helps cause the accidents. It takes a different route from my tentative guess about controlling other factors, but it supports the same explanation.
Does the pattern prove causation? No. Something else could still be involved. But evidence needn't prove an explanation to strengthen it. The closer match between the timing of drowsiness and the timing of the excess accidents makes sleep deprivation a better-supported candidate.
- E
Effects lasting several days don't establish that lost sleep explains the accident spike on the following day. We aren't given an accident pattern over those later days to connect with the lingering effects. D provides that kind of useful connection for the period we're actually examining.
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