Hey — great q —
I believe that looking for both commonalities and differences, and trying to understand both, is essential to effective LSAT prep, and it’s especially true here —
Those three q types — Flaw, Supporting Principle, and Sufficient Assumption, do most certainly have a lot of overlap, but each of them presents a very specific task, and, in order to maximize your chances for success, you really want to make sure you are tuned in to those exact tasks the questions present.
So for those three q types, I won’t go into full detail here (you have the book for more of that stuff), but the biggest commonality comes in the mindset these q’s should inspire in you for how to read the stimulus —
For all three, you want to do your best to —
1) Read with empathy to try and correctly understand the author’s point, and the reasoning he/she is using to get to that point, as accurately as possible.
2) Try to understand as clearly as possible why the reasoning the person gave is not enough to guarantee the conclusion the person reached.
These are your most important tasks for all these three q types (as well as the majority of other q’s you will see in LR) and if you perform these two steps well you put yourself in great position no matter what q type it is (and, on the flip side, if you don’t perform these steps well, no amount of q strategy can make up for it).
Additionally, another commonality amongst these q types is that if you do gain firm control over the argument and reasoning, you will typically be able to eliminate the majority of answer choices because they have no direct bearing the author’s point, or how he/she is trying to support it.
Finally, in terms of the right answers, there is great commonality in the functions they serve and the “feelings” they bring about —
Right answers to all three tend to have an “additive” effect for the argument — they help prop up or address issues —
Furthermore, the right answers to flaw and principle (we are talking about support / confirm principle q’s here, btw) q’s speak directly to the given argument — you can check them directly against the conclusion and support and they should speak about the actual issue between them.
And the right answers to principle and suff. assumption q’s will commonly address the issues in a way we find very satisfying — in ways that seem to “take care” of the problem.
So, off the top of my head, those are some of the more important commonalities to consider in terms of your experiences with these q’s —
In terms of the important differences / unique characteristics —
I think a big key is just to be as literal as possible and not try to outsmart the given task — so some of my advice may seem a bit overly obvious —
For Identify the Flaw —
If you’ve read the stimulus well, the last thing you will be thinking about as you go into the answer choices is what is wrong with the argument, and so the right answer to a flaw q should, most of the time, match-up very well to what you are thinking about. And you should expect the substance of the right answer to be predictable (in terms of substance).
And perhaps just as important as having a right understanding of the flaw is having a right sense of the bandwidth that the ultimate right answer can fit into — that is, the ways in which the right answer will be different from what you anticipate —
For a flaw q —
1) it should be highly unlikely that the right answer will address a different issue than what you found (to visualize, almost all arguments have one big clear gap, as opposed to lots of different little gaps).
2) it is, however, very likely that the right answer represents the reasoning problem from a different perspective than the one you had (the simplest example of this being you thinking about something the author took for granted while the right answer discusses things the author failed to consider).
3) it is also very likely that the test writer will describe the flaw using different words than you would use, and, the more difficult the q, the more likely the test writer will describe the flaw in an awkward or unexpected way.
4) right answers can describe the flaw in more general/abstract ways, or they can describe them more specifically using the details of the stimulus — you ought to be open to an answer that is more specific or generalized than what you have in your head.
For a principle q –
1) A principle is, by definition, a more generalized or abstracted understanding, so, your instinct should be that the right answer will address the gap in some generalized way.
2) Wrong answers are thus very commonly wrong for generalizing incorrectly – by taking details from the stimulus and putting them into broader groups that don’t belong, or making statements too extreme relative to what the evidence warrants.
3) Just anecdotally, I think you need to be a bit more open to right answers for principle q’s “hitting the gap” in a less satisfying way than flaw answers do — it doesn’t have to be this way — it’s per the preferences of the test writer, but keep in mind that principle q’s don’t require you to fully, perfectly, fix arguments, and so you shouldn’t expect/require that in a right answer. A supporting principle is defined just by supporting (just as a strengthen answer just by strengthening) and the degree of support doesn’t determine right or wrong.
For suff assumption q’s –
1) A sufficient assumption is, by definition, something that makes an argument completely valid. This is a very clearly definable task, and so the sense you’ll get with right answers for these q’s should feel, on average, much more black and white than for a lot of other q’s.
2) The right answer to a suff assumption question is not meant to be predictable, and, though one can waste a lot of time/energy trying to predict them, it’s not worth it. Sometimes you will be able to predict the right answer well and other times you won’t, and that’s not necessarily a sign of anything or important for anything. (The takeaway being that it’s much more important to understand correctly the gap to be filled, as opposed to how one might fill it).
3) Because suff. Assumption q’s are about absolutes, they tend to be dependent on conditional logic, which is the logic of absolute reasoning (must, only if, etc.). You should expect to utilize your conditional reasoning skills far more often here, and, on the flip side, they can be very useful for helping you see when your conditional reasoning skills aren’t as strong as they can/should be.
4) So, the key to consistent success on Sufficient Assumption Q’s is
a) being very, very good at understanding very clearly exactly which (clearly defined) gap needs to be filled &
b) being very, very good at testing whether different answers fill that gap absolutely or not.
That’s all of the top of my head — forgive me if I’ve missed something huge (and if anyone sees so please feel free to chime in) — obviously there is more advice in the book —
I hope that helps — again, these q’s are inherently related and require a lot of common skills, but it is essential you treat each one as a unique, individual task —
To illustrate with just one quick final thought — if you were a test writer and wanted to create a tempting wrong answer to a sufficient assumption q, how might you do it?
One cruel way would be to write an answer that seems to address the gap in the argument, using the words that a student would likely use in his or her own head in thinking about the flawed reasoning, but doesn’t actually completely guarantee the validity of the conclusion. Meanwhile, you also happen to tuck in a right answer that is totally unexpected, brings up random things, but nevertheless performs the task of making the argument perfectly valid.
By trying to focus on being as specifically oriented to the given task as possible, you make yourself far less vulnerable to tempting wrong answers, and you make it much easier on yourself to develop the right habits for each type of q.
Sorry for the length and if you have any follow-up q’s just let me know – MK