#12 - Impact craters caused by meteorites smashing into

[Francis O'Rourke]

Hi Andriana,

You will come across causal relationships in the premises of a stimulus. When this happens you are able to diagram these statements. The only things that you need to consider are if diagramming will help you understanding of the information, and how much time you will need to invest in diagramming the statement.

[biskam]

THis stimulus really puzzled me because I had trouble understanding the reasoning in the argument, meaning I didn't understand that lower rates of geophysical processes meant earthquakes, volcanos, etc, and thus that lower rates of these might "erase" evidence of craters (particularly the erasure part).

In the face of dwindling time, I tried to mechanistically look for "new info" in the conclusion and match it to an answer choice (B), which ended up being wrong.

This isn't the first time I've struggled understanding the reasoning behind an argument in a LR stimulus. Sometimes I'm completely stumped on how an alleged argument even makes sense.

Do you have any tips on what to do in these situations? or how to better dissect confusing meaning?

Thank you!

[Adam Tyson]

Take a look at the earlier answers in this thread, biskam, and especially at Ricky's response showing that "lower rates of destructive geophysical processes" was not actually new info in the conclusion.

As to your more general question about how to deal with confusing, difficult arguments, there are a few things you can try to get a better handle on things. First, my favorite is to paraphrase the argument in the simplest abstract terms. Strip away the confusing details and get to the core of the argument. In this case, that looks to me to be something like this:

There's this phenomenon that shows up mostly in one type of place (an effect).

It must be because that type of place has a special characteristic (a cause).

To justify this causal conclusion, I need to eliminate every other possible cause.

Now, as it happens, in this case I don't think the correct answer DOES justify the conclusion. I think it only strengthens it. There still could be other causes. Perhaps the evidence in the less stable regions was obscured by human activity, while the stable places are remote and there is no such activity? Maybe our alien overlords decided to clean up those other places and leave the stable ones alone? It's hard - really hard! - to justify a causal argument, because they are so inherently flawed. Still, this answer at least eliminates an alternate cause of sorts, and so it is the best answer of the bunch, even if it is a bad answer, and since we are supposed to pick the best answer we must pick this one.

Another approach to confusing arguments is to look for key language, or indicators, which may be present in the argument. Conditional language, for example, should stand out, as should the language of comparison/analogy, and those indicators may give you some clues as to how to attack or support an argument. Here, it's a bit subtle, but "explained by" is causal language - the presence of one thing explains the presence of another if it causes the other. Catching that subtle hint here should set you on the path of seeking to eliminate alternate causes, show that where the cause is present the effect is also, etc.

Finally, and this is a difficult one for many of us, you must give up on the idea of making sense of the arguments. Arguments can be a bunch of baloney, so long as they have a logical structure and so long as the author at least appears to believe that certain claims (premises) support other claims (conclusions). Follow the underlying logical structure of the argument, and don't worry about how much sense it makes to you. You can treat an argument like this one the same way you would treat an argument made up of nonsensical statements, and attack it structurally. For example:

Minnesotans are allergic to walnuts, and monkeys prefer convertibles to comic books, so my cousin must be home this weekend.

Now, justify the conclusion. How? Tell me that either that allergy, or that preference, or both together, prove that my cousin will be home. Find an answer that links one or both premises to the conclusion in a way that erases all doubt. Forget sense, forget the real world, and focus on the logical structure of the argument (and in this case, because it is a justify question, focus on the gap between the premises and the conclusion and close it up).

The authors want you to get lost in the details. They want to confuse you and distract you and mislead you at every turn. It can be even worse on reading comp, if the topic is a dense one (science for some people, art and literature for others, maybe economics if that isn't your thing) and you allow yourself to focus on the details rather than the structure, the tone, the arguments, the viewpoints, etc. Don't get bogged down in details, ever! Strip them away and get to the core, the abstraction, the structure. Use key language, or paraphrasing/abstraction, or whatever you need to do to get there.

That's your mission, should you choose to accept it. Good luck!

[biskam]

Thanks for the motivation Adam!! I appreciate it. Fundamentals that I often forget

[Snomen]

Can anyone please explain why B is wrong...?

[Snomen]

In addition, can anyone please provide any tips on how to figure out the conclusion in this type of argument.., I thought that the Conclusion was in the first sentence after "but". It was really confusing.

[Adam Tyson]

A conclusion is only a conclusion if the author has given you a reason to believe it, snomen. That comes in the form of evidence, aka premises, that the author offers in support of that claim. There is no evidence to support the claim that impact craters "have been found in the greatest density in geologically stable regions." We are just supposed to accept that as a fact, with no evidence other than that the author said so, so it cannot be a conclusion.

A key helpful phrase in this stimulus is found in the second sentence: "must be explained by." The author is saying in that second sentence that the phenomenon described in the first sentence has to be caused by the lower rates of destructive processes there. We could paraphrase that sentence as saying "the places with craters are more stable than those without, therefore that stability must be why." Look for the claim that the author supported with at least some evidence, and that's a conclusion! Unsupported claims cannot be conclusions.

Answer B doesn't help that argument any, and might even hurt, because it means that the places that are currently stable might once have been unstable. If that's so, and if instability erases evidence of impacts, then why are there still impact craters there? At best that answer muddies the waters, rather than proving that instability erases the evidence while stability preserves it.

[cgleeson]

Hi,
This one is a tongue twister for me. I think however, I may understand the reasoning. The author is stating that there have been meteor impacts all over the planet, however, the one that are the most preserved are the ones that have been examined in areas of "lower destructive geophysical" occurrences. The question is asking how can that conclusion be possible. (I think for me the problem was understanding the passage, and I thought I did) The correct answer choice D is saying that there have been meteor strikes all over the earth, and the areas where there are less natural disasters the craters are just preserved better.
I had picked E out of frustration and I see why that is wrong, it doesn't support the fact that there are meteor strikes all over it's just that the best preserved ones are in areas of less natural disasters (Volcanos, earthquakes, floods).
Am I understanding this correctly? Many thanks
Chris

[Beth Hayden]

Hi Chris,

Right on the money! A big problem with the conclusion is that it leaves open the possibility that the meteorites just happened to hit mostly in certain areas. Answer choice (D) rules out that possibility: if the meteorite impacts have been scattered evenly, but the craters are concentrated in certain regions, the explanation makes more sense.

Answer choice (E) provides an alternative potential explanation for why more craters were found in those areas, but it actually doesn't do anything for the conclusion, which claims that geological stability is the reason why there are more craters there. If the conclusion is an explanation for a phenomenon, a different explanation is probably not going to be helpful to that conclusion.

Hope that helps!
Beth

[jwooon]

Hi,

I am a bit confused about the assumptions that the stimulus makes. I figured that in my prephrase the AC will either say (1) destructive geophysical processes destroy meteorite processes (confirms an assumption made by the last sentence) or (2) the amount of meteorite falling is consistent in areas with lower rates of destructive geophysical processes as well as in areas with higher rates of destructive geophysical processes (eliminates alternative reasons). Now (D) I realize is the same as my 2nd prephrase, which helps, but I feel like (A) is very similar to my 1st prephrase? If meteorite restriking is a destructive geophysical process, it must happen more in regions with higher rates of destructive processes, therefore more likely to destroy the craters there.

I feel like even in my interpretation (D) is a stronger AC than (A), but I fail to see how (A) does not justify the conclusion.