Conditional reasoning diagram

[hihither]

Hey guys,

I have so much trouble to draw down diagrams whenever I encounter conditional reasoning in some question types. I can easily figure out the sufficient and necessary relationship when it is given to me in a short paragraph but if it’s embedded in longer questions I can’t figure out connection the relations together. What should I do?

Sometimes when I look at must be true questions or most strongly supported questions I do better without doing the diagram...

[Jeremy Press]

Hi hihither,

To help you better, it would be very useful if you could provide some specific examples of statements, or stimulus paragraphs, where you're having trouble diagramming. As always with conditional reasoning, the "devil" is often in the details, and there are some very helpful guides we can give for specific statements.

In a general sense, remember two things: you're right that there are some instances of conditional reasoning that don't require complete diagramming to answer correctly. I often find this to be the case on simple Must Be True questions, Flaw questions, simple Principle questions, and the occasional Justify or Assumption question (where the correct answer is a conditional statement).

But, there are some questions where it's very difficult to prephrase, and even more difficult to distinguish answer choices, if you don't map out the reasoning in the stimulus. These include (non-exhaustive list) Must Be True questions with multiple conditional statements (where a chain of conditional diagramming is often necessary), Parallel Reasoning questions with multiple conditional statements (again, to see the "chain" of reasoning), and some Principle questions.

In every case where you need to diagram, it comes down first to identifying the statements that are conditional via the common conditional indicator words. So it really is necessary to memorize the most common indicators of sufficient and necessary conditions.

Second, you must learn to quickly "carve" the conditional statement into its constituent parts. It's easy to do this if you have two indicators words, like an "If....then...." statement, where each half of the conditional relationship is clearly marked off. It gets more difficult to do this when only one indicator is present. Then you need some rules of thumb to clearly define the "end point" of one conditional piece, and the "beginning point" of another conditional piece. For example, in statements that begin with the word "Only..." or the phrase "Only if...," the necessary condition will be the first portion of the sentence, and its end point is the main verb in sentence. The sufficient condition is found after the main verb. An example would be: "Only if you submit an application to law school will you be permitted to attend." Here, the necessary condition ends before the main verb "will," and is the notion of "submitting an application to law school." The sufficient condition is found after the main verb, and is the notion of being "permitted to attend law school." Rules of thumb like this for discerning the parts of the conditional relationship are essential to "carving" each statement into its constituent parts quickly, and then diagramming them accurately.

If you have some specific examples, we'd be happy to provide more tips on this process, but I hope this helps for now!

Jeremy

[hihither]

Hi Jeremy,

Thanks for your quick reply. Yes I think in some must be true questions or most strongly support question I can do it without diagramming.

Like this one I have so much trouble connect the relations like this one

“Only an expert in some branch of psychology ....
Which one of the following conclusions can be validly drawn from the passage?
(A) Patrick does not ...
(B) Patrick is not a...
(C) Patrick is not ...
(D) Unless Charles ...
(E) If Charles is certain ..."
[admin note: full text of LSAT question removed due to LSAC copyright regulations]

Even simple questions like these I have so much trouble connecting the relations together. I always have to look up on the forum to look at the the right diagram. I. Don’t know how else I should improve on getting the right diagram relationship :/

[KelseyWoods]

Hi Hihither!

It would help to know more about how you would diagram this problem yourself to determine what's really giving you trouble. But basically, you take it one conditional relationship at a time and look for similar terms.

So you start with the first sentence--how would we diagram that? It has an "only" and that's a necessary indicator so that means that the part of the sentence modified by "only" is going to go at the end of our arrow, on the necessary side. The remainder of the sentence then becomes sufficient.

Understand why Patrick is behaving irrationally Expert in some branch of psychology

Then we look at the next sentence. "No expert is capable of solving someone else's problem" means the same thing as "If you are an expert, you are not capable of solving someone else's problem. So we diagram it like this:

Expert Capable of solving someone else's problem

The last sentence doesn't have a conditional, it just tells us that Patrick wants to devise a solution.

Now we look at the conditionals we have and see if they have any conditions in common. An "expert in some branch of psychology" is also just an "expert." So we can combine those two conditional statements using the term expert:

Understand why Patrick is behaving irrationally Expert Capable of solving someone else's problem

Take out the middleman and it becomes:
Understand why Patrick is behaving irrationally Capable of solving someone else's problem

Take the contrapositive and you've got:
Capable of solving someone else's problem Understand why Patrick is behaving irrationally

That leads us to answer choice (E).

Again, it would be helpful to know more specifically about which part of the process trips you up. Is it identifying indicator language? Knowing which condition is sufficient and which is necessary? Finding similar terms that can be combined? Taking contrapositive? Talk us through your thinking process with these a bit more.

Hope this helps!

Best,
Kelsey

[hihither]

Thank you!