Summarize Argument: Phenomenon-Hypothesis
The author concludes that ads aired at supermarkets are effective. He supports this with a study showing that consumers who checked out within 40 minutes of hearing an ad were more likely to buy the product than those who checked out before the ad aired.
Notable Assumptions
The author assumes that there are no alternative hypotheses that explain the correlation between customers hearing the ad and purchasing the advertised product. He assumes customers weren't already planning to buy the product and that the increase in purchases isn’t just a coincidence. He also assumes that the study reflects the effectiveness of all supermarket ads.
A
During the study, for most of the advertisements more people went through the checkout lines after they were aired than before they were aired.
Irrelevant. The argument addresses whether people were more likely to buy the product, not how many people bought the product. So it doesn’t matter when more people checked out.
B
A large proportion of the consumers who bought a product shortly after the airing of an advertisement for it reported that they had not gone to the store intending to buy that product.
This rules out the alternative hypothesis that most customers who bought an advertised product were already planning to buy it that day. This makes it more likely that the ad influenced their purchase.
C
Many of the consumers reported that they typically bought at least one of the advertised products every time they shopped at the store.
This doesn’t help to establish that the advertisement itself caused people to buy the product. Also, (C) doesn’t say which consumers reported buying an advertised product every time they shop— maybe the consumers in (C) didn’t even hear the ad.
D
Many of the consumers who bought an advertised product and who reached the checkout line within 40 minutes of the advertisement’s airing reported that they could not remember hearing the advertisement.
Irrelevant. Whether people remember hearing the ad doesn’t tell us whether they actually heard it. If they didn’t hear it, this would weaken the conclusion that the ad influenced their purchase.
E
Many of the consumers who bought an advertised product reported that they buy that product only occasionally.
Irrelevant. The fact that people only buy the product occasionally doesn’t explain whether the ad influenced their purchase on this occasion. They might have already planned to buy it that day.
"Surprising" Phenomenon
Why do traffic congestion and delay problems increase after widening and extending highways in urban areas?
Objective
The correct answer should suggest a difference between having wider, more extended roads and having less wide, less extended roads. This difference should create the potential for more congestion when roads are wider and more extended.
A
Widened and extended roads tend to attract many more motorists than used them before their improvement.
Wider, more extended roads could lead to more congestion by attracting a lot more drivers. This effect could more than outweigh whatever decrease in congestion the physically wider roads create.
B
Typically, road widening or extension projects are undertaken only after the population near the road in question has increased and then leveled off, leaving a higher average population level.
We’d still expect wider roads to lead to less congestion. Maybe these projects only occur in highly-populated areas; wider roads can still allow people to drive more freely and with less delays.
C
As a general rule, the greater the number of lanes on a given length of highway, the lower the rate of accidents per 100,000 vehicles traveling on it.
It’s not clear how the accident rate relates to congestion and delay.
D
Rural, as compared to urban, traffic usually includes a larger proportion of trucks and vehicles used by farmers.
The discrepancy involves urban areas. A comparison to rural areas doesn’t explain why wider, more extensive roads in urban areas leads to more congestion.
E
Urban traffic generally moves at a slower pace and involves more congestion and delays than rural and suburban traffic.
The discrepancy involves urban areas. A comparison to rural areas doesn’t explain why wider, more extensive roads in urban areas leads to more congestion.