Q20 - A new gardening rake with

[YLAGUNAS]

I struggle with sufficient and necessary questions, and this one is one of them. I do not understand why A is the answer (I think the "the only" at the beginning of the answer choice is throwing me off). Please help!

[timmydoeslsat]

I struggle with sufficient and necessary questions, and this one is one of them. I do not understand why A is the answer (I think the "the only" at the beginning of the answer choice is throwing me off). Please help!

This is a sufficient assumption question. One of these answer choices will allow the conclusion to be drawn.

The conclusion in this stimulus is that the straight handle rakes are better than the new rakes for minimizing spinal injury.

The evidence provided tells us that:

New rake has less compression stress on spine in the pull stroke.
New rake has more compression stress on spine in the push stroke.
Old rake's compression stress is not enough to cause injury to the spine on the push and pull strokes.


As of right now, this evidence looks really good in favor of the old rake, the straight handle. The problem is in the conclusion, it does not state to minimize compression stress to the spine, but rather to minimize injury to the spine.

We have only been told about these rakes and their issue with compression stress on the spine. We do not know that compression stress is the only way to have an injury to the spine.

Perhaps the old rake is above the danger level in hyper-extending the spine?

Choice (A) gives us the ability to conclude the idea of spinal injuries overall, as if it were true that compression stress from pushing were the only cause of spinal injuries, we know that the old rake is better in terms of minimizing risk.

[imperial.franco]

Sorry for reviving this post. But I have the same concern as that of Ylagunas regarding the qualifier "only."

Does the answer choice really have to include the qualifier "only" rather than simply stating, "compression causes injury to the spine?"

What if there are other factors that the new rake has that also causes injuries to the spine? If so, wouldn't the answer choice, "Compression stress resulting from pushing is the only cause of injuries to the spine that occurs as a result of raking" be too restrictive in that he does not have to assume that it is the "only" cause?

[ohthatpatrick]

Yes, the answer does need to have "the only" to work.

It seems like you're just confusing Sufficient Assumption with Necessary Assumption.

You said "he would not need to assume ...". We're not doing Necessary Assumption.

On Necessary Assumption, going overboard is bad. (strong ideas are super dangerous and should be red flags)

On Sufficient Assumption, going overboard is great. (weaker ideas are super dangerous and should be red flags)

We need to GUARANTEE the truth of the conclusion. That's our task on Sufficient Assumption. We're not judging answers based on "did the author have to assume this". We're judging answers based on "if this were true, would it GUARANTEE the truth of the conclusion?"

With all arguments in the Assumption Family, I want to figure out how the Conclusion could still be false (i.e. "How could I argue the Anti-Conclusion?")

In this case, considering the anti-conclusion, we'd have to argue that straight-handled rakes are NOT better than new rakes for minimizing risk of spinal injury. How can we do that? It seems tough to make that argument.

After all, we know that the push and the pull stroke of the straight rake does NOT produce enough compression stress to cause injury.

So with the straight rake, there is NO chance of a compression stress spinal injury.

With the new rake, the push stroke is above the danger level.

So with the new rake, there is SOME chance of a compression stress spinal injury.

If the straight rake has NO chance of a compression stress spinal injury and the new rake has SOME chance, then isn't the conclusion right? Isn't the straight rake better at minimizing risk of spinal injury?

The only way out of this corner is to argue that a straight rake could cause a spinal injury some OTHER way besides compression stress. That's the only way the straight rake could have more risk of injury.

Because when it comes to compression stress, the straight rake clearly wins.

That's why (A) is sufficient to prove the conclusion.

If compression stress is ALL we can consider, THE ONLY thing, then straight rakes win!

With Sufficient Assumption, there's no reason to characterize the wrong answers. They're wrong because they're not right! They DON'T provide the missing link or rule out the one possible objection.

(B), (C), (D), and (E) don't prove the conclusion because they don't rule out all other ways the straight rake might lead to spinal injuries. That is the only idea that matters in terms of whether or not the conclusion is true.

Hope this helps.