Logical Reasoning - Do You Diagram Everything? Forum

[perspective]

I am looking for some advice on how to improve my Logical Reasoning. One of my professors and an acquaintance both mentioned their success at diagramming all of the problems. I take it that they mean applying conditionals and representing relationships between the sentences through the use of p,q, etc.

Is that correct? If it is, does anyone have any recommended readings for how to diagram the various relationships?

I will compile the information given throughout this thread in the next post for anyone else who might be interested!

Edit: Please limit discussion to:
1) How to Diagram relationships
2) Relationships
3) Examples of Diagrams

[perspective]

Reserved for a brief guide on Logical Reasoning.

[Cole S. Law]

I diagramed nothing. I averaged less than -2 and was always done with the LR sections with at least 4 min to spare. I would think that diagramming would be too much of a time suck to be valuable. Perhaps on an individual problem that perplexes you, but for every question it seems like a waste.

[Zatarra]

You may find a range of responses for this question, so absolutely try out a few possible methods, and see what works for you.

That said, I diagrammed very little, if anything for the LR. The key, for me at least, was quick, rapid processing of each question. With the exception of highly convoluted language or complex conditionals, after doing enough practice you should be able to remember and process each question well enough to tackle the answer choices without any notation. Again, aside from a few particularly complex questions, I would actually recommend against a 'diagram, diagram, diagram,' approach, as this can slow you down, and introduce the possibility of diagramming errors. For what it's worth, after some practice, I'd rarely miss more than a question or two on an LR section.

But, I've seen some people (and courses) swear by a more diagramming focused method, so results may vary!

[perspective]

During practice tests I would like to practice on all of the problems so when test day comes I can be comfortable with it. I should have asked that the thread be restricted to discussion on 1) how to diagram, 2) the various constructions (conditionals, etc) that can be encountered, and 3) sample diagramming situations.

For those unfortunate few who are cursed with a weak LR ability I think diagramming would be the safest way to achieve -0.

[holydonkey]

Diagramming is a big help. I'd definitely recommend getting in the habit. You don't need a special book, even a general Kaplan or Princeton Review book has enough good info on this.

[TUP]

The powerscore logical reasoning bible is often recommended, although I haven't used it personally.

For those of you that don't diagram at all, did you use the bible? Or strictly PTs and review to prep for the LR section?

[quasi-stellar]

Using diagrams for every question is really not a good idea. Besides, in all honesty, you seriously dont need to.
However, occasionally you will come across some formal logic questions where setting up a quick diagram would be helpful,
since you need to map out certain relationships to see the entire chain of reasoning. Other than that, i wouldnt bother.

[tomwatts]

On Inference and Sufficient Assumption ("The conclusion follows logically if which one of the following is assumed?") questions, diagrams can be very useful. On S.A.'s in particular, diagrams can just tell you the right answer without you have to understand much of anything. But on other question types, I'm not sure that diagramming is a terribly good idea, at least as a frequent thing.

[chocho]

LR was one of my stronger sections, -4 on the whole test for LR (175ers laugh), I only diagrammed the questions that gave you a logical chain and said something like, what assumption allows this to be true, or what must be true etc etc

[fiathebia]

where are you guys learning these diagrams? i only know how to diagram formal logic from the bibles. is it possible to diagram every question?

[splay]

The only questions I diagram for on LR are the "which of the following arguments follows the same structure" questions. Can you actually diagram the others? This intrigues me.

[LegalGENius]

No time to diagram everything

[tomwatts]

The only questions I diagram for on LR are the "which of the following arguments follows the same structure" questions. Can you actually diagram the others? This intrigues me.

Much of the time, you can diagram Inference and Sufficient Assumption questions (which is what chocho referenced posting after me). If you're given something of the form...

"All widgets are doohickies, and all gizmos are thingamabobs, so all gizmos are doohickies.

Which of the following, if assumed, allows the conclusion to be properly drawn?"

You can then say:

P (for Premise): w -> d
P: g -> t
C (for Conclusion): g -> d

So what I'm trying to do is make a chain of arrows that says g -> d. What I have right now is g -> t and w -> d. If I had t -> w, this would work, because I'd have g -> t -> w -> d, which does g -> d for me. So the right answer needs to say "All thingamabobs are widgets," or potentially the contrapositive, "Anything that's not a widget isn't a thingamabob."

You can do similar things with Inference questions.