Explain | Video lesson

- [Instructor] In this question we're asked, which one of the following, if true, would most help to explain the apparent discrepancy described above? We can identify this question as an Explain Question. The answer will provide information that makes the situation in the passage make sense and the four wrong choices, why they're not help the situation make sense, or, make the situation even more puzzling than it is. Pause your video now if you'd like to try this question on your own. Otherwise, let's move on to the explanation. Okay, let's read the stimulus together and as we do, just focus on describing the discrepancy in your own words. Don't think about the answer yet. "The number of deer living in North America "has increased dramatically since the 1960s, "even though hunters kill no fewer deer today. "Moreover, the number of natural predators of deer, "such as wolves, is on the rise, "and suburbs increasingly encroach on deer habitats." So with Explain Questions and Resolve Questions, our first job is to describe the situation that doesn't seem to make sense. We're told here that there are more deer living in North America since the 1960s. Great, but we also learned that hunters kill no fewer deer today than they used to, and we also learned that the number of deer's natural predators is increasing, and, that suburbs are encroaching more and more on deer habitats. If we take all of the information together, we would actually expect there to be fewer deer living today, right? So, lots of threats to deer are flourishing, and yet, the number of deer has increased dramatically. So let's phrase the discrepancy as a question. Why are there more deer today, even though so many deer threats have increased? We don't need to make a prediction for these question types, because there could be so many possible explanations. The most important piece is to understand the discrepancy in a very clear way. Now, we move to the questions and evaluate each one against the discrepancy that we observed. We'll ask, does this choice, as information, provide the light bulb that we're looking for? Does it make us say, ah, okay, now I understand why there are more deer living today, even though so many deer threats have increased? Let's do it. Choice A. "Pesticides that adversely affected most wildlife "living in North America "have been banned since the 1970s." Let's think about the impact of this information. If pesticides that hurt most North American wildlife were banned since the 1970s, that would explain why there are more deer. They're no longer being hurt by the pesticides. That means that a potentially major threat to deer has been removed. Even though other threats are on the rise, it is reasonable that this threat is more important, so on test day, we could select this and move on to a new question. Let's look at the wrong choices, in case you have questions about them. B, "Recently, attempts have been made "in various parts of North America to protect deer habitats "from suburban development." This doesn't help us. First of all, we don't know how recently these protective attempts have been made, and we also don't know how effective those attempts were. We don't know which parts of North America are counted when it says, "various parts," meaning we don't know if those are significant parts, so we have to add way too many assumptions to justify this choice, and that's never a good thing when evaluating a choice on test day. Choice C. "The number of deer hunters in North America "has decreased since the 1960s." At very first glance, this could be tempting, because it seems like a good thing for the deer, if the number of deer hunters has decreased, but remember what the passage told us. "Hunters kill no fewer deer today." So even though the number of hunters has gone down, the hunters who are left are still killing as many deer, if not more. So the mystery remains. D reads, "Much of the increase in the population of wolves "is due to wolves born in captivity "and released into the wild." Okay, so this is explaining why there are more wolves, but not at all why there are more deer. We can rule this choice out since we know that our task is to explain the increase in deer. Finally, E states, "The greater the number of deer, "the more likely they are to be afflicted with problems, "such as famine and disease." This doesn't help explain why there are more deer today. In fact, if anything, it makes the situation even more surprising. Since we're told the number of deer has increased dramatically, we would expect them to be more hurt by problems such as famine and disease. So a choice that makes the situation even more surprising, is the opposite of what we're looking for in an answer. So to recap, for Explain Questions, you're reading with the purpose of formulating the discrepancy, and it's really helpful to form a question around it, if you can. Why are there more deer today, even though so many threats to deer have increased? Then, pretend that each choice is a proposed answer to that question, and pick the one that actually does answer the question and shed light on the situation.