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 Otunga
 Posts: 1317
 Joined: Fri Mar 15, 2013 7:56 pm
Re: Help on LR !!
It doesn't work here, unless it's a rare sufficient assumption question where the answer is both necessary and sufficient to assume, though I'm not sure that's ever turned up in a sufficient assumption question  I think it's happened in a nec. assumption question.
Essentially, you don't need to assume sufficient assumptions. They're good enough to get you to the conclusion, or perhaps they go above and beyond what you need, but the point is that you could still plausibly draw your conclusion without assuming them. Saying you need 100 coins and then assuming you have 101 isn't necessary, but assuming you have at least 100 is necessary. Negating that you have 101 would not necessarily hurt the argument, as you could still have 100, or 102, or 1000 or 100000.
Essentially, you don't need to assume sufficient assumptions. They're good enough to get you to the conclusion, or perhaps they go above and beyond what you need, but the point is that you could still plausibly draw your conclusion without assuming them. Saying you need 100 coins and then assuming you have 101 isn't necessary, but assuming you have at least 100 is necessary. Negating that you have 101 would not necessarily hurt the argument, as you could still have 100, or 102, or 1000 or 100000.
 Christine (MLSAT)
 Posts: 358
 Joined: Fri Nov 22, 2013 3:41 pm
Re: Help on LR !!
Yeah, don't use the negation test. While it may work in a few cases, it's likely not to, and you're just going to get yourself completely turned around. In most cases, negating it will simply remove one potential path of many from the premises to the conclusion, so the argument won't die at all.
You need to think of sufficient assumptions and necessary assumptions as just two different mindsets. Not mutually exclusive ones, obviously, but thinking about anything having to do with 'necessariness' is just a distraction when you're looking for something sufficient.
Think of sufficient assumptions in purely positive terms: if it's true, it guarantees the conclusion.
Think of necessary assumptions in purely negative terms: if you take it away, the argument falls apart.
Completely ignore the entire thought process for the one you are not testing.
You need to think of sufficient assumptions and necessary assumptions as just two different mindsets. Not mutually exclusive ones, obviously, but thinking about anything having to do with 'necessariness' is just a distraction when you're looking for something sufficient.
Think of sufficient assumptions in purely positive terms: if it's true, it guarantees the conclusion.
Think of necessary assumptions in purely negative terms: if you take it away, the argument falls apart.
Completely ignore the entire thought process for the one you are not testing.

 Posts: 145
 Joined: Mon Jun 30, 2008 4:07 pm
Re: Help on LR !!
Sufficient Assumption questions are virtually always shifts in scope. (Apples and Oranges sort of thing)
The correct answer will link the mismatch in the ev and the mismatch in the concl (only with a broader scope). Often the answer is written as: If <evidence>, then <conclusion>. (Just a broader restatement of the argument as a whole).
People hate these questions, but they're VERY predictable. Beware the negation approach if you stumble on an overlooked possibilities SAQ, you're going to end up getting it wrong.
The correct answer will link the mismatch in the ev and the mismatch in the concl (only with a broader scope). Often the answer is written as: If <evidence>, then <conclusion>. (Just a broader restatement of the argument as a whole).
People hate these questions, but they're VERY predictable. Beware the negation approach if you stumble on an overlooked possibilities SAQ, you're going to end up getting it wrong.