#15 - Main point

[cardinal2017]

It was a tricky main point question.

I initially chose answer (E) bx it quite appropriately addresses the big issues in the passage.

However, I see (C) is more proper as a final answer now since it is more inclusive or comprehensive in implying every point of discussion in the passage.

(E) doesn't address the second paragraph at all in that it doesn't address
the problem concerning plant growth, or doesn't contain the aspect of differential increase in plant growth, which was one of the big issues in the passage.

[Jonathan Evans]

Hi, Cardinal,

Good job reasoning through this problem. Let's discuss how we could develop an accurate prephrase to help us choose the correct answer from the outset.

I often like to conceive of the main point to RC passages in three steps:

1. What is the topic of the passage?
2. More specifically, what does the passage say about this topic?
3. What is the author's point of view about this topic?

In other words, start with the big concept that the passage is all about. Then consider specifically what the passage discusses in relation to this concept. Finally, what's the author's take on this discussion? What's the point. For example, here my thought process might look something like this:

1. What's the topic? Global warming
2. More specifically, what does the passage say about this topic? It's a discussion of whether increased CO2 levels will actually cause higher crop yields, or whether more plants might offset global warming.
3. What's the author's point of view? The author thinks more CO2 actually won't do all the good things some people think it might.

The answer to my third question more or less accurately paraphrases (and prephrases) the main point.

Compare this prephrase to Answer Choices (C) and (E). For (C), we have an excellent match. For (E), we seem to have a partial match, but there are some issues: First, about plant growth, this is not exactly what the author is getting at. She's actually stating that the increased plant growth might differentially benefit some plants (weeds) over other plants (crops). Second, while we might assume that global warming could increase because of the increased decomposition rate at higher latitudes, this issue of rate is not the central point of the second part of the discussion. Thus, while (E) matches somewhat in scope, it has significant issues in matching the main ideas the author tries to express.

To develop this point somewhat, consider the overall structure or purpose of this passage. The passage is organized thus: (1) Idea presented. (2) One possible opinion about this idea offered. (3) Author addresses and rebuts this opinion.

This structure is not at all uncommon, and through practice, you should endeavor to recognize it. It is akin to:

• Some experts claim smoking is actually beneficial for your health, but I wanna know what these experts are smoking. Smoking increases risks of heart disease and lung cancer, so it's obviously not beneficial for your health.

I hope this helps!

[Legalistic]

Hello,

I initially chose (B) as my correct answer. Even though I now understand why (C) is a better answer, I'm having trouble understanding the word "contradictory" in answer choice B. I personally thought that while the author was concluding that increased CO2 levels would not lead to a lush green world, that would eventually decrease the rate of global warming, his premises (the studies he cites) to support his conclusion, had yielded contradictory findings with "some research" in lines 6-15 about the benefits of increased CO2 levels on agricultural productivity.

Does B mean to say that the author's findings (premises - recent studies) contradict with his own conclusion of "increased CO2 levels would not lead to a lush green world, that would eventually decrease the rate of global warming"? Is that why it's wrong? (I mean, I know it doesn't fully encapsulate the main point of the passage but I need another reason to discount it considering my initial thought process while reading answer choice B)

Can you please give me a clear meaning of answer choice B? and explain to me where I went wrong and how I should have approached this question?

Thank you in advance (like so much!)

[KelseyWoods]

Hi Legalistic!

The studies cited in the passage do not necessarily yield contradictory findings. "Contradictory findings" means results that conflict with one another, findings that are mutually exclusive or cannot both be true. The conclusions that people make based on the findings described in this passage are overstated, but the findings themselves do not contradict each other. It can be true that plant growth would be generally enhanced in an atmosphere rich in CO2 AND that the increased CO2 would differentially increase the growth rate of different species of plants, eventually resulting in decreased agricultural yields. The findings (the CO2 fertilization effect being generally beneficial for plant growth, but affecting different species of plants differently) do not directly contradict one another, rather they contribute to a more complete picture of the effects of increased CO2 in the atmosphere. That's why the author argues that some conclusions others have drawn from the initial findings about increased plant growth due to the CO2 fertilization effect are overstated because they do not consider how CO2 might affect different species differently.

But even if you think that these findings are contradictory, remember that in Main Point Questions, there are often answer choices which are true, based on the passage, but they are not the Main Point. So if you think an answer choice is true but does not encapsulate the main point of the passage as well as another answer choice, that's plenty of reason to eliminate it!

Hope this helps!

Best,
Kelsey

[lsatquestions]

I was stuck between B and C but eliminated B for another reason - the MP is not about agricultural productivity.

[Adam Tyson]

But it is about that, lsatquestions! Some people think that increased CO2 will lead to "a lush world of agricultural abundance," which means thriving crops and more food production, but our author thinks this is false because it's really the weeds that will thrive instead of food crops. Agricultural productivity is at the heart of the whole passage! The real problem with answer B is that the findings are not contradictory, and that in any event the main point is not what the findings are but that those findings indicate that the view expressed by some as described in the first paragraph is wrong.

[attorneyatpaw]

I was also between (C) and (E) but ultimately eliminated (E) because the statement "the rate of global warming would ultimately increase" felt too strong. Most of the evidence the author provided used language like "suggests" and "simulation" which didn't necessarily point to a definitive conclusion. Did I have the right idea or did I just get lucky?

[Jeff Wren]

Hi attorneyatpaw,

You're correct to note the differences in levels of certainty between the passage and Answer E. Often wrong answers to Must Be True questions (and Main Point question) are exaggerated and are worded more strongly than is supported by the stimulus/passage. Good job paying attention to words such as "suggest." These types of words indicate a cautious tone and often appear in science passages in which the author doesn't want to overstate the claims/results. Often these passages end with a "but more research is still needed" caveat.

This is one reason that Answer E is wrong, and it only takes one reason to eliminate an answer, even though there may be (and often are) more than one reason that the answer is wrong.

Knowing that this passage follows a very common pattern of argumentation found in LR and RC in which one viewpoint is given and then the author disagrees with that viewpoint helps prephrase a main point similar to Answer C. As soon as your read "some research has suggested ..." in lines 6-7, you should be expecting that the author will likely disagree, and that this disagreement will likely be the author's main point.