PT127 · S1 · Q13 Consumer advocate: A recent study

This argument is comparing washing machines of different types (front loaders vs. top loaders). So clearly the author is comfortable comparing washing machines of a given type with washing machines of some other type.

The author doesn't need to assume that convenience is the only important factor. He definitely is assuming that it is an important factor. And he's assuming that the advantage front-loaders have in terms of convenience for wheelchair users isn't outweighed by other important factors. If we negate this and say that "there are other important factors to consider beyond just convenience", that does weaken the argument somewhat, because it creates room for doubt. It allows us to think, "ooh, maybe some of the other important factors tip towards top-loaders. So who's to say whether wheelchair users would think that overall front-loaders are superior." It's very weird for there to be a wrong answer choice that definitely does weaken when you negate it. But if we go by the standard of, "Which answer, when negated, most weakens?", we'll always find the right answer on Necessary Assumption. (That is not to say we should always use this standard, because negating all the answers is often more difficult than other ways of finding the correct answer. But if we're on the fence between two answers, asking ourselves which negation most weakens is a great tie-break.) Which weakens more? negated (A): for no users would the convenience of front-loaders outweigh the advantages of top-loaders in terms of overall superiority. negated (C): there are other important factors besides convenience. (A)'s negation weakens more because it totally shuts down the possibility of using this evidence to prove superiority. (C)'s negation just creates the possibility that other factors might outweigh this evidence.

Necessary Assumption loves to write trap answers like this. If the paragraph says, "Black lives matter", the trap answer says the argument is assuming "non-black lives don't matter". Here, the paragraph said, "removing clothes from a top-loader is highly inconvenient for wheelchair users". So this trap answer is saying "removing clothes from a top-loader is not inconvenient for non-wheelchair users." We're never allowed to take a sentence and just invert its terms that way. If we say, "people who serve in the military are heroes", that doesn't mean "people who don't serve in the military are not heroes". It's possible that for non-wheelchair users, removing clothes from a top-loader isn't highly inconvenient, it's just mildly inconvenient. The argument doesn't need to assume that it's actually convenient. The argument isn't even concerned with non-wheelchair users.

Again, the argument doesn't care at all about people who are not wheelchair users. It's trying to support a conclusion that says, "for at least some people, front-loaders are superior", and we can tell that the 'some people' the author has in mind are wheelchair users. So the author's whole argument is just trying to convince us that for some wheelchair users, front-loaders are superior. He doesn't need to assume anything about non-wheelchair users. If we negate this and say that non-wheelchair users also find it convenient to unload clothes from a front-loader, that wouldn't weaken. In fact, it would come closer to agreeing with the author's conclusion.