Question

Over a period of several months, researchers attached small lights to the backs of wetas—flightless insects native to New Zealand—enabling researchers for the first time to make comprehensive observations of the insects' nighttime activities. Thus, since wetas forage only at night, the researchers' observations will significantly improve knowledge of the normal foraging habits of wetas.
Which of the following is an assumption on which the argument depends?

• A. Researchers were interested only in observing the wetas' foraging habits and so did not keep track of other types of behavior.
• B. No pattern of behavior that is exhibited by wetas during the nighttime is also exhibited by wetas during the daytime.
• C. Attaching the small lights to the wetas' backs did not greatly alter the wetas' normal nighttime foraging habits.
• D. Wetas typically forage more frequently during the months in which the researchers studied them than they do at other times.
• E. The researchers did not use other observational techniques to supplement their method of using small lights to track the nighttime behavior of wetas.

Hint:

To test if a statement is a necessary assumption, use the "Negation Test." Negate the statement and see if the argument falls apart. If we negate (C) to say "Attaching lights did greatly alter the wetas' habits," then the conclusion that the researchers learned about normal habits is no longer supported. This proves (C) is a necessary assumption.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
This is an assumption question. An assumption is an unstated premise that is necessary for the argument's conclusion to be valid. The argument concludes that the observations will improve knowledge of the insects' normal habits. We need to find the hidden belief that connects the observation method to this conclusion.
Step 2: Detailed Explanation:
Argument Breakdown:
\begin{itemize} \item Premise: Researchers used a new method (attaching lights) to observe wetas at night. \item Conclusion: These observations will improve knowledge of the wetas' \textit{normal} foraging habits. \end{itemize} The logical leap is from "observing with lights" to "understanding normal habits." For this to be a valid conclusion, the method of observation itself must not interfere with or change the behavior being observed. If attaching lights scared the wetas or made them behave abnormally, the researchers would not be learning about their normal habits. Therefore, the argument must assume that the lights did not significantly affect the wetas' behavior.
Let's evaluate the options:
\begin{itemize} \item (A) The researchers' other interests are irrelevant to whether this specific method works for observing foraging. \item (B) The argument is about nighttime habits; daytime habits are irrelevant. \item (C) This is the necessary assumption. If the lights did alter the habits, the conclusion would be invalid. The argument depends on the assumption that the observation method was non-intrusive. \item (D) The frequency of foraging during the study period is not relevant to whether the observation method is valid. \item (E) Whether they used other techniques is irrelevant to the validity of this specific technique. \end{itemize} Step 3: Final Answer:
The argument's conclusion about understanding "normal" habits depends on the assumption that the method used to observe them did not make their behavior abnormal.