Medical researcher: Scientists compared

Answer choices

1. A

   Too Weak4% picked this

   For both groups of joggers compared by the scientists, the rate of jogging injuries during the study was lower than the

   This doesn't show any difference between the two groups. Because the rate of injuries in the study is lower than the average rate of jogging injuries in the population, we might try to interpret this answer as saying that the study wasn't an accurate rendering of jogging injuries. But that's a weak line of attack compared to the correct answer. The fact that the two groups had the same number of injuries still looks like a sign that stretching isn't making a difference (unless the # of injuries for both groups was essentially zero).

   4%
2. B

   Too Weak7% picked this

   Among the joggers in the groups compared by the scientists, many of those previously injured while jogging experienced difficulty in

   If we found out that many people in the stretching group didn't stretch, that would taint the data. We would be like, "Well this isn't a fair way to measure the effects of stretching -- lots of the stretching group didn't even stretch!" But "Many experienced difficulty" doesn't mean that anyone in the stretching group didn't stretch. It just means they winced a little the way older people with frailer bodies often do when they're warming up their bodies.

   7%
3. C

   Opposite14% picked this

   Most jogging injuries result from falls, collisions, and other mishaps on which the flexibility resulting from stretching would

   This strengthens the idea that stretching does little to prevent jogging injuries, since most jogging injuries couldn't really be affected by stretching.

   14%
4. D

   Correct64% picked this

   The more prone a jogger is to jogging injuries, the more likely he or she is to develop the habit

   Why this is right

   This allows us to point to a meaningful difference between the two groups: the stretching group was more prone to jogging injuries than the non-stretching group. If we re-read the wording of the study, it doesn't say that the experimenters took a large group of similar people and randomly assigned some to the stretching group and some to the non-stretching group. It allows for the possibility that the stretching group was self-selecting. This answer is helping us argue that "the stretching group was full of people who already knew they were prone to jogging injuries (the older or more frail or previously injured folks)". Imagine you saw a game of full-court basketball between some 40 year old dads and their 20 year old kids. The 40 year olds would all stretch, knowing they have gimpy backs and trick-knees, and such. The 20 year olds wouldn't bother stretching; their bodies still feel invincible. If the 40 year olds ended up incurring the same number of injuries as the 20 year olds, that would be a big win for the 40 year olds (who should be way more prone to injuries). That would suggest that stretching helped them. Similarly, if stretching before jogging is making these injury-prone joggers end up with the same number of injuries as the non-stretching healthier joggers, that's a win for stretching.

   Skill tested: Weaken · how this choice captures the argument's function is the move to repeat next time.

   64%
5. E

   Out of Scope: "severity"12% picked this

   Studies have found that, for certain forms of exercise, stretching beforehand can reduce the severity of injuries

   The conclusion is about whether jogging helps to prevent injuries, not whether it helps to lessen the severity of injuries. Also, "for certain forms of exercise" needn't refer to jogging, so this answer would have very weak impact since it would only suggest that "maybe this applies to jogging".

   12%