Each year, an official estimate

Answer choices

1. A

   Correct36% picked this

   Last year’s official estimate was probably not much different from the official estimate

   Why this is right

   The "official" estimate is the one obtained by averaging the two separate estimates (the commercial one and the research sampling one). Since, over the last ten years, one of the numbers has increased by about the same amount as the other one has decreased, the average will come out to be about the same. Picture a married couple: Gabe and Luke. Ten years ago, Gabe made $90k and Luke made $80k. The "official estimate" of their household income would average those two numbers together and get $85k. Over the last ten years, Gabe's salary has increased by about the same mount as Luke's has decreased. So now Gabe makes $100k (+10) and Luke makes $70k (-10). The "official estimate" of their household income is still $85k.

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

   36%
2. B

   Causal Speculation52% picked this

   The number of commercial vessels fishing for cod in the Grand Banks has increased substantially

   If there were more vessels doing commercial fishing, then that could explain why the research team's estimate has gone down. (The more cod removed from the water by commercial fishing, the lower the stock of cod in those waters, and so the research team's estimates would show there are less cod than before) But two problems: 1. This is speculative. We have no support for this being the reason that cod in the water are decreasing (if they are). It could be a lot of other reasons. 2. This kind of goes against the fact that Method 2 (commercial tonnage) is rising. After all, that stat is "how many cod did you catch per hour (per km of net)". The more competing vessels there are fishing in the same place, the less cod you'd probably catch per hour.

   52%
3. C

   Unsupported Comparison6% picked this

   The sampling-based estimate is more accurate than the estimate based on commercial tonnage in that the data on which it relies is

   We have no reason to give preferential deference to one estimate vs. the other, nor can we support the idea that one form of data is less likely to be accurate than the other. Sure, I trust researchers with data more than I do commercial fishers, but the researchers go out once per year whereas the commercial fishers are collecting data every day, so their set of data is much more robust.

   6%
4. D

   Too Strong1% picked this

   The once-yearly sampling by research vessels should be used as the sole basis for arriving at the official estimate

   Too Strong: sole basis Out of Scope: should Just like (C), this answer seems to immediately assume that the research team has the better estimate, but we have no support for that. It is also a huge leap away from "what can we derive from these facts" to suddenly have a strongly-worded opinion: should be sole basis.

   1%
5. E

   Out of Scope: twenty years ago6% picked this

   Twenty years ago, the overall stock of cod in the Grand Banks was officially estimated to be much larger than it

   We weren't given any information about twenty years ago. And given that the official estimate is obtained by averaging together the two separate estimates, since one of those two has gone up and the other has gone down, we don't have any support for the idea that the official estimate (the average of the two) is higher or lower than before.

   6%