Self-study
Researcher: This fall I returned to a research site to recover the armadillos I had tagged there the previous spring. █████ █ █████ ████████ ██ ███ ██████████ █ ██████████ ████ █████ ██████ █ ███ ███████ █████ ██ ███ ████████ ██ █████ ███████ ████ ███████ █ █████████ ████ ██████████ ██ ███ ████ ███████ ████ ███ ████████████
Summary
The researcher concludes that armadillos don’t move rapidly into new territories. To support this claim, she refers to the results of her research. After tagging armadillos in the fall, she returned in the spring to recapture them, with the majority of those recaptured being close to their original fall locations.
Notable Assumptions
The researcher assumes that the recaptured armadillos did not travel to new territories after being tagged and then come back before being recaptured in the spring.
She also assumes that she recaptured enough armadillos to draw this conclusion; if she initially tagged 100 but only recaptured 20, then the remaining armadillos could very well be in new territories.
11.
Which one of the following ██ ██ ██████████ ████████ ██ ███ ████████████ █████████
a
Of the armadillos ██████ ██ ███ ████ ██ ███ ███████ ████ ████ ███████ ███ ████ ████ ██ █████ █████ ██████ ██ ███ ███████████
We don’t care how many armadillos were initially tagged, only about how many were recaptured. Even if she only tagged half the armadillos in the area, she would still have a large enough sample to draw her conclusion.
b
Most of the ██████████ ██████ ███ ████████ ██████ ████ ███ ██████████ ██████ ███ ██████████ █████
This answer choice is related to one of the researcher’s assumptions—that she recaptured enough armadillos to draw her conclusion— but it instead weakens the argument. We want to know that most of the armadillos were recaptured, not that they weren’t.
c
Predators did not ████ ███ ██ ███ ██████████ ████ ███ ████ ██████ ███ ████████ ███████
Like (D), this answer choice is too strong. Even if a few tagged armadillos were killed by predators, there would still be enough remaining for the researcher to draw her conclusion.
d
The tags identifying ███ ██████████ ██████ ██ ███████ ██ ███ ███████████ ██████ ██ ████████ ██ █████████████
Like C, this answer choice is too strong. Even if the tags could technically be removed by the armadillos, we don’t know if they actually will be, or if enough will be removed to impact the results of the study.
e
A large majority ██ ███ ██████████ ██████████ ███ ███ ████ ██ █ ███ █████████ ██ ███ ███████████ ██████ ███ ████ ████ ████ ██ ███ ███ █████████ ██ ███ █████
The author believes that recapturing the armadillos in the same place she tagged them is evidence that they don’t move quickly into new territories. If (E) is not true—the armadillos moved during the summer and came back afterwards—recapturing them provides no evidence that they didn’t move, and the conclusion is undermined.