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Identify an entailment | Worked example

Watch a demonstration of one way to approach a question that asks you to identify an entailment that follows logically from a set of premises. Created by Sal Khan.

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  • blobby green style avatar for user njurechko
    This is nottt EZ to learn. Thank u for making the videos free. Please please keep them free! They are needed!
    (11 votes)
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  • blobby green style avatar for user A A
    Question Type: Identify an Entailment

    This is a great example of an inference question in which, despite all the clutter, only one sentence actually matters. In this case, it's the last sentence: "one or the other of these sources of funding [government or corporate] is necessary for any genetic research."

    That information alone is enough for us to realize that answer (D) must be true, because as you put it, if there's no corporate funding and no government funding, then there's no research, and hence no ethical dilemmas arising from research!

    All the other answer choices try to lure us into mistakes concerning the other information in the stimulus.

    (A) is incorrect because although we know that government is the exclusive funder of most genetic research, we have no idea which genetic research leads to advances. Maybe all government-funded genetic research goes nowhere, and the minority of research that's funded by corporations is responsible for all of the advances! Because we don't know, we don't have support for this answer.

    (B) is wrong because, again, we have no idea how much or which research leads to advances.

    (C) see above!

    (D) is correct because it says that "No ethical dilemmas "resulting from advances in genetic research arise without government or corporate funding."

    (E) is tempting, but the stimulus only tells us what's true currently about genetic research. We have no idea whether this will continue to be the case, or whether it will change.
    (7 votes)
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  • blobby green style avatar for user a a
    Why is At least some advances in genetic research occur in projects funded by corporations false? What would make this a must be true statement?
    (1 vote)
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  • blobby green style avatar for user kyndalsagee
    The type of conclusion is causation right?
    (1 vote)
    Default Khan Academy avatar avatar for user

Video transcript

- [Instructor] Almost all advances in genetic research give rise to ethical dilemmas. Government is the exclusive source of funding for most genetic research. Those projects not funded by government are funded solely by corporations. One or the other of these sources of funding is necessary for any genetic research. Alright. If all of the statements above are true, then which one of the following must be true? Now before I even look at these choices, let's diagram this out a little bit. So this first statement says almost all advances in genetic research give rise to ethical dilemmas. So let me draw a little diagram. So let's say that this is, this right over here, these are all the advances in genetic research. All advances from genetic research. Now they're not saying all of the advances lead to ethical dilemmas, they're saying almost all of the advances. So I would say almost all. So this is almost all of them. So these are the ones we could say lead to ethical dilemmas. Ethical dilemmas. Alright, now what do they go on to say? They say government is the exclusive source of funding for most genetic research. Those projects not funded by government are funded solely by corporations. One or the other of these sources of funding is necessary for any genetic research. Okay, so this is interesting. So the next thing we want to think about is well, not all research leads to advances. So, let's do it like this. So this is all of the research, a subset of which leads to advances. So that's all the research, all of the genetic research. And then this research is going to be funded either by government or by corporations. They make that very clear. One or the other of these sources of funding is necessary for any genetic research. So this is going to be government or corporations. Alright, now that we've diagrammed this out a little bit-- And we're assuming that, we have to assume that all of this is true. This might not actually be true, but if we assume they're all true, which of theses statements must be true? Most advances in genetic research occur in projects funded by government rather than corporations. Well, that might be the case, but it doesn't have to be true. It's possible that the corporate funding is actually responsible for most of the actual advances. Maybe they fund better in some way, or they're more effective in some way. So that one definitely does not have to be true, even if we assume all of these statements are true, you could have a world in which the corporations somehow fund the research that has all the advances in it while the government funding isn't as effective. So I would rule that one out. Most genetic research funded by government results in advances that give rise to ethical dilemmas. They're saying that research is funded either by government or by the private sector or by corporations. So this is the research right over here. They're saying that look, some of it is funded by government, and some of it is funded by corporations. Now they say most genetic research funded by government results in advances that give rise to ethical dilemmas. Well we don't know that most of the research funded results in advances. It might be a small amount of either that result in actual advances. Once again we have to pick the thing that must be true. So if we can figure out a situation that well, it doesn't have to be true, then we can rule it out. At least some of the advances in genetic research occur in projects funded by corporations. Well once again we're not picking something that might be true or that sounds reasonable, we're trying to pick something that must be true. And I can construct a situation where all of the advances are sitting squarely on the government's side of what they are funding. On this diagram right over here, maybe this is the stuff that the government is funding, and all of the corporate research doesn't lead to any advances. Now it might not seem likely or reasonable, but that could actually be the case that all of the advances are happening on the government side. So we don't have to say that at least some of the advances in genetic research occur in projects funded by corporations. It feels like a reasonable statement, but it doesn't have to be true. No ethical dilemmas resulting from advances in genetic research arise without government or corporate funding. So these statements up here they're saying we have these ethical dilemmas from advances in genetic research. That's this green area here. These are ethical dilemmas from the advances. And they're saying no ethical dilemmas resulting from advances in genetic research arise without government or corporate funding. So if we took away the government and the corporate funding, the statements up here tell us that corporate and government funding are the only sources of research. Well then this research won't happen, in which case these advances won't happen, in which case you will not have these ethical dilemmas from the advances. So this statement must be true. Now let's look-- Let me delete some of this marking up I did. So this needs to be true. Now let's look at this last choice. As long as government continues to fund genetic research, that research will give rise to ethical dilemmas. Well, once again it might feel like a reasonable statement, something that might be true, but it doesn't have to be true. For example, all of the advances might be occurring in the corporate research. So if this one right over here, that might be the government and this might be the corporate. All of the advances are happening in the corporate research, and some of them are causing the external ethical dilemmas. Maybe all of the government research is very inefficient. And in that case, that research will not give rise to ethical dilemmas. So this does not have to be true. We definitely wanna go with D.