Sufficient Assumption

[Henry Z]

I wonder if there's a direction factor in the PowerScore Mechanistic Approach? What does it mean by "link"?

I know we find SA by linking new elements. My understanding of "linking" is to put the new element in the premise on the left side of the arrow, while the new element in the conclusion on the right:
Premise: A—>B
Conclusion: A—>C
Ans: B—>C

However, in the below example, SA seems to be found by linking conclusion (left) to the premise (right), not the other way around:
Premise: B—>C, e.g. Everyone in Manhattan hates the subway;
Conclusion: A—>C , e.g. Joan hates the subway;
Ans: A—>B, e.g. Joan is in Manhattan.

I don't think SA can be B—>A, e.g. Everyone in Manhattan is like Joan (clumsy wording i know).
Because we’ll then get B—>A & C, not A—>C.

I read the PowerScore Mechanistic Approach section, it only says linking new elements, but doesn't specify how to link. I used to think it means putting new element in the premise on the left side of the arrow, and putting new element in the conclusion on the right side. But now I'm confused.
Can someone confirm if my analysis of the second example is correct and maybe elaborate more on how to link the new elements?

[atierney]

So, it's important you're asking about a sufficient assumption, so that in your example, and in general, the conclusion is to be made true. . This means, that we are really working backward, and providing a missing premise that allows us to prove that the conclusion is true. Now, I'm not where you found the specific notation you mentioned in your post, but I would say the notation should look like this:

A ---> C

B ---> C (specific conclusion)

ergo

B--->A (the missing "link").

Anything that you have seen to the contrary I would disregard. As a general note, I think it's important to recognize that where your common sense conflicts with notation, i.e. where notation causes a city to be in a person, I would take the side of common sense.

Let me know if you have any questions on this.

[Henry Z]

Thanks, atierney, for your quick reply.

Just to confirm: when we look for NA (a Supporter, not a Defender) by linking the new elements, we just put the new element in the premise on the left side of the arrow, and new element in the conclusion on the right side. But when looking for SA, we can't always do that, as the direction of the linking depends.

Do I understand the Mechanistic Approach correctly?

[atierney]

Yes, that's correct. The idea is to find the link that best matches the new information, wherever that new information may be found, in the stimulus or the conclusion with SA questions.