Logical Reasoning

PT101 · S3 · Q5 Bacteria from food can survive

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Bacteria from food can survive for several days on the surface of plastic cutting boards, but bacteria can penetrate wooden cutting boards almost immediately, leaving the surface free of contamination.

Conclusion (therefore)

Wooden cutting boards, unlike plastic cutting boards, don't need to be washed in order to prevent them from contaminating future food cut atop them. Wiping off the food debris is sufficient.

Evidence

Bacteria on wooden cutting boards penetrates the surface almost immediately, leaving the surface free of contamination.

Whereas on plastic cutting boards, bacteria from food can survive for several days on the surface.

Evaluate

We could predict a Missing Link assumption based on the thing we say about wooden cutting boards in the premise and the thing we say about it in the conclusion:

But we might be wise to also come up with an Objection, by thinking through the Anti-Conclusion.

Given that ... the bacteria penetrates the surface almost immediately and leaves the surface free of contamination,

How could we still argue that ... wooden cutting boards do need to be washed in order to prevent contamination risk?

Maybe bacteria underneath the surface can still contaminate food that's cut on a wooden cutting board?

Goal

Let's look for an answer that links the premise language to the conclusion language, or look for an answer that, when negated, hurts the argument and makes it seem like you do need to wash wooden cutting boards or else the bacteria might contaminate future food.

Which one of the following is an assumption on which the argument depends?

Washing plastic cutting boards does
Out of Scope: washing plastic
The argument never discusses the effects of washing plastic cutting boards, other than to imply that plastic cutting boards do need to be washed in order to prevent their contaminating food that is cut on them. But the author doesn't need to assume that washing is less than 100% effective. If we negate this and say, "Hey, author -- washing plastic cutting boards doesn't remove 100% of bacteria", would that weaken? No that has no effect on the argument. The author can still argue that washing plastic cutting boards needs to be done, even if it's only 99% effective.
4% picked this
Prevention of bacteria contamination is
Too Strong
Too Strong: the only Only Thing Mentioned ≠ Only Thing Just because the only "superiority" the author mentioned about wooden cutting boards is that the bacteria leaves the surface almost immediately, that doesn't mean she's assuming that this is the only superiority that wooden cutting boards have. If I say, "Hey, you should visit San Francisco. The Golden Gate bridge is beautiful", am I assuming "the only reason to visit SF is that bridge? the only beautiful thing in SF is that bridge?" Of course not. Just because it's the only thing I mentioned doesn't mean I think it's the only thing. If we negate this and say, "Wooden cutting boards have other superiorities too", that wouldn't weaken. That wouldn't help us argue that wooden cutting boards do need to be washed.
2% picked this
Food that is not already
Too Strong
Too Strong: only Only Thing Mentioned ≠ Only Thing Like (B), this is taking the only thing mentioned and acting like it's the only thing. We only discussed food getting contaminated by bacteria on cutting boards, but there's no reason to think this author believes that cutting boards are the only way for food to get contaminated with bacteria. We could cough on the food or drop it on the floor and make it contaminated. The author doesn't dispute any of that. She's only talking about contamination in relation to cutting boards.
2% picked this
Correct
Bacteria that penetrate into wooden
Why this is right
This has the lovable "ruling-out" not that is involved in so many correct answers on Necessary Assumption (we call these Defender answers, because they're defending against an objection). When we see these "not" answers, we can easily negate them and ask ourselves whether the negation would weaken. If we say to this author, "Yo -- bacteria that penetrate into wooden cutting boards do reemerge on the surface after the cutting board has been used", would that weaken? Sure! That gives us a way to argue that wooden cutting boards do still need to be washed. The author felt like they were risk free because the bacteria almost immediately leaves the surface and penetrates into the board. But if we say, "Yeah, but the bacteria climbs back up to the surface later", then the wooden cutting board does not have a risk-free surface.
Skill tested: Necessary Assumption · how this choice captures the argument's function is the move to repeat next time.
90% picked this
Washing wooden cutting boards kills
Out of Scope: washing wooden
The author doesn't say anything about what effect it would have to wash a wooden cutting board. She's telling us that we don't need to wash a wooden cutting board, so she isn't expressing any opinions about what washing one would do to bacteria below the surface.
3% picked this

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