purpose of diagraming Forum

[LaEstelle2009]

did the 7sage course on how to diagram but i guess i am horrible about it because i do not understand the purpose of it.
when am i supposed to diagram?
do you actually have time to make a diagram when pt'ing and on test day?
what book is the best to understand diagramming?
have any of you found it helpful?

[ScottRiqui]

If you're talking about diagramming logic games, then yes - it's necessary. I'm sure there are some "Rainman" types who can hold an entire game in their head, with all its rules and interactions, but I've never met anyone who can do it reliably.

The purpose of diagramming a game is to give you a visual representation of the "game pieces" that are in play, along with the locations that those pieces can/can't occupy. Any of the books should be enough to get you started; with the exception of the Velocity LSAT system, most of them are just minor variations on a theme.

[LaEstelle2009]

diagramming for logic reasoning such as: A->B B<->C therefore some A's are C's or something like that

[ScottRiqui]

diagramming for logic reasoning such as: A->B B<->C therefore some A's are C's or something like that

Ah, gotcha - you had me worried for a bit there. No, I generally didn't diagram anything in the Logical Reasoning sections unless the question practically begs for it; you'll recognize those questions, since they're basically a series of logical statements written out in plain English rather than symbolic form, and you'll be asked to draw some kind of conclusion from them. Even then, I don't translate them to symbolic form unless they're tricky or confusing.

[JamMasterJ]

diagramming for logic reasoning such as: A->B B<->C therefore some A's are C's or something like that

usually the only time I diagrammed these things was when there were multiple if/not/unless type modifiers that were basically code for (draw an arrow or a / or something). The majority of them aren't multilayered formal logic

[Louis1127]

I am not a 170 + scorer by any means, but I do what jammasterj does. Whenever there are conditions that seem like they may link up with each other (usually via the contrapositive) and I cannot keep track of them in my head, I take time to draw it out.

[KDLMaj]

There are a few instances where you MUST write out the FL. But most of the time, there's really no point.

1) Parallel Reasoning/Flaw Qs with FL in them (This is their favorite type these days- if you don't write it out you're asking to make a silly mistake)

2) Inference Qs with FL (Most- but not all- Inference Qs are nothing more than a test of your ability to combine ideas. If you see FL in an Inference Q and *don't* write it out- you're being sloppy and asking for trouble. A lot of people on these boards love to say things like "Oh I never write them out, and I'm awesome". Often times they're the same ones who later post things like "I keep missing 4-5 Qs in LR, but I don't know why!".

3) Occasionally in heavy FL assumption Qs. Though- contrary to popular belief- FL is almost never required for them. (In the sense that contrapositives are almost never required, and the evidence and conclusion are rarely both examples of FL outside of a handful of the harder Suff Qs) Basically, if you need it, you'll know. The one potential exception is scope shift arguments where the relationship is "Evidence is needed for the conclusion". (The format of these arguments is always Not X because Not Y- where X and Y are unrelated concepts-, and the answer choice is always going to be: X is needed for Y with a likely tempting wrong answer choice that reverses it showing up before the correct answer. But you only see 1 or 2 of these max on any given test)

Otherwise, just because you see one statement like "Everyone at the party had a drink" doesn't mean you have to jump into full-on FL mode. Know which question types are likely to actually test true FL concepts and which ones won't.