Diagramming and When To Pull Out This Time-Consuming Technique

Logic Gainz

I usually try and complete questions containing a stimulus riddled with formal logic in my mind, but sometimes that burns me because although the structure isn't too complicated (i.e. no embedded clauses or anything), the answer choices could be structured in a way that is a bit harder to decipher if you don't have a diagrammed structure written down somewhere. Refer to the example in Preptest 82 below:

https://7sage.com/lsat_explanations/lsat-82-section-1-question-19/

I was just wondering if there is anyone out there that avoids this issue altogether by habitually diagramming stimuli that are heavy with formal logic, or if you guys generally do what I do and try to keep things in your mind, and then diagramming after you figure out that the diagrams might be more than your working memory can handle - especially when some of the arguments require taking the contrapositive. I guess I want to see how competent I am compared to someone doing well with formal logic stimuli. If you guys generally keep the structure in your mind, then that tells me I have more work to do in understanding formal logic at first glance, or on the other hand, maybe needing to diagram out the argument isn't just common, but efficient when it comes to getting through a logical reasoning section.

10000019

Hey can you specify the question type. I don't have access anymore. Without knowing the question type, I'll broadly weigh in.

I would never diagram an LR question on first pass. I very rarely diagrammed an LR question on second pass.

Early in studying, I relied on diagramming for parallel questions. I ended up doing a lot better on parallel questions when I stopped diagramming.

I think diagramming while reviewing is fine, but under timed conditions you need to quickly make the connections internally.

And to address your "keep things in your mind":
What are your referring to? If you're talking about internalizing the diagram you could have explicitly drawn, then no I didn't do that either.

nmmizokami

I asked this question a while ago and the consensus was that diagramming on paper is a tool used rarely and only for the more difficult questions (under timed conditions). High scorers are able to diagram most questions mentally but sometimes are forced to do it on paper when the arguments are more convoluted.

Nunuboy1994

You mean like making a diagram for an LR? Yes, some people do this. My friend who scored a 179, tutored me a couple of times and drilled into my head If A then B; But if not b then that does not necessarily mean not A. The power score LR bible discusses diagramming conditional logic. She said on the day she took the test, my friend, that she did a couple of small diagrams in the LR section and underlined every conclusion. Hope this helps

eRetaker

I spent a lot of time on my formal logic so I didn't really need to diagram on paper. If I did diagram, it would be on a tough parallel reasoning or MBT question. Probably 1 or 2 questions per test?

LouisLitt

@Nunuboy1994 said:
You mean like making a diagram for an LR? Yes, some people do this. My friend who scored a 179, tutored me a couple of times and drilled into my head If A then B; But if not b then that does not necessarily mean not A. The power score LR bible discusses diagramming conditional logic. She said on the day she took the test, my friend, that she did a couple of small diagrams in the LR section and underlined every conclusion. Hope this helps

The contrapositive of "if A then B" is "if /B then /A". It does necessarily mean not A.

Nunuboy1994

No the LSAT contrapositive is if not b then not a

LouisLitt

@Nunuboy1994 said:
No the LSAT contrapositive is if not b then not a

Right that's what I am saying.. the contrapositive of A ==> B is /B ==>/A. In your first post that I quoted, you wrote "If A then B; But if not b then that does not necessarily mean not A", which is false. Not sure where I'm losing you..

Adam Hawks

I think it sort of is an instinctual thing that you have to develop to an extent. I've seen conditional logic in NA questions (sometimes when needing to bridge), SA questions, MBT, and the parallel families. Usually you just have to be on the lookout when they start throwing in indicators. Take your time in the BR process and you'll begin to see the patterns.

keets993

Sometimes, yes. It depends on the individual. I found out that I was making overconfidence errors by not diagramming so I figured why not take the extra 15-30 seconds to diagram and guarantee an easy point. Diagramming also boosted my confidence with questions that I was not conifident about. I don't diagram right away though, like it's not robotic that the moment I read "if" I start diagramming but I read through the stimulus and the answer choices and then decide.

Bamboosprout

I circle them and leave these questions to the end. That way, you have plenty of time to slowly diagram them. This question isn't too bad though.

Do a bunch more of these logic heavy questions and you shouldn't even need to diagram it. Contrapositive should be automatic by the time you finish the core-curriculum. If not, hopefully doing the logic section one more time will do the trick. Good luck!

Leah M B

I only rarely diagram LR questions. Generally, the only ones I occasionally do are either MBT or MBF. Those questions are intended to be somewhat confusing and I find that sometimes I need to quickly write out the conditions, because then I can very quickly find the answer. However, on questions like the one you referred to, it's not too confusing and pretty simple. So, I find that I can relatively easily track that in my mind and remember it. Once I find the right answer, I might refer back to the stimulus quickly just to double check, but that structure is typically simple enough that I can do it in my head and not waste time writing.

Logic Gainz

These have all been really helpful comments, team! @10000019 , the example given in the link was a parallel reasoning question. The stimulus in the argument is simple, hence why I didn't diagram, but answer choice A uses a contra. I missed it upon first read.

@Nunuboy1994 your friend's LR approach is interesting. Nathan Fox says never to underline in an LR argument and to write as little as possible, but your friend's score clearly justifies that underlining conclusions can work for some people. I'll have to give this a try.

The general consensus seems to be to diagram as little as possible if you can help it. Obviously there are some stimuli for which a diagram will help, but that should be the exception and not the norm.