Q 16 versus Q 17

[Xantippe]

Q 16 asks: The primary purpose of the passage is to...

Q 17 asks: Which of the following statements best expresses the main idea of the passage?

How are these questions fundamentally different and how can I distinguish between the two questions?

Is it fair to interpret the first, (Q16) as asking me what the author is primarily doing with the passage? I answered (B) present some recent scientific research on the function of the platypus's bill. Whereas in (Q17) I am being asked what overall is the passage telling us? The correct answer, which I got wrong is; (B) Neurophysiological studies have established that the platypus uses its bill to locate its prey underwater.

Thanks in advance, the sequence of the questions caught me off guard during my PT and I want to learn how they are different.

[Adam Tyson]

That order is unusual, Xantippe! I can't at the moment recall any other examples in the past 20 years since this particular test where the Main Point question was anywhere other than first, except perhaps in Comparative Reading where we might get asked the main point of one of the two passages. There may be some, but it's very rare!

The big difference between Main Point and Primary Purpose is exactly as you described it - well done! I usually tell my students that Main Point is "what is the passage all about," while Purpose is "why did the author write it?" or "what did they author hope to accomplish?" Main Point answers delve into the details, and either restate the author's thesis or else give a good summary of the key information in the entire passage. Purpose answers almost always (always?) start with a verb - "demonstrate" or "argue" or "criticize" or "compare," and so on. They often make no mention of the details, although they can. A Purpose answer might say "compare two theories and suggest that the second is more persuasive than the first." The Main Point answer, though, would have to tell us something about what that second theory is about.

In short, Main Point is about what the author said, while Purpose is about what the author did, or tried to do.