#16 - People who do not believe that others distrust them

[meghana]

Hi Nikki,

I have the same question as the person above and I did read your explanation, but I am still confused.

I did set the diagram up correctly (below I use words to stand in for each component):

premise: /believe others distrust --> confident --> challenge
conclusion: trust --> challenge

So, I understood that "/believe others distrust" and "trust" needed to be connected. I plugged in "trust" AFTER "/believe others distrust", like this:

/believe others distrust --> trust --> confident --> challenge.

I realized I messed up when I saw that C was the only answer that related these 2 components so I knew it had to be right, but it does so in the reverse of my prephrase.

Why is my prephrase wrong? How do you know where to plug in "trust" (that it goes BEFORE "/believe others distrust" and not after)? Is it because my way disrupts the premise and C does not do so?

I want to understand so I don't repeat this mistake in the future!

[Rachael Wilkenfeld]

Hi Meghana,

You are exactly right---your prephrase would break up the conditional.

We have if
B C
C D

Conclusion A D

If we put A B, we have a nice chain, and it links together smoothly.
If we put B A, we don't have that same sort of chain. We'd have two separate chains that don't link up. It would look something like this

B C D
B A

But we couldn't use that to draw the conclusion A D. A could occur in this set without D, because we don't have anything coming off that A. We can't draw any conclusions about what happens if A.

We want to make sure as we link up that we keep A in the sufficient condition, to show that A forces something to happen, which will force D to occur. That's why the A B matters here.

It is great that you isolated the correct variables though! It sounds like it was enough to get you to the right answer.

Hope that helps!

[Roadto170]

Just wanted to attempt to explain the stimulus so I know that I understand it. Please feel free to correct me if I am incorrect or err in some way.

This stimulus has two premises and a conclusion. For each independent statement, I am going to assign a letter to simplify the process. Premise: Confident (C) > Difficult task is a challenge (D). Premise: (Not) Believe Others (-B) > Confident (C). Conclusion: Trust Others (A) > Difficult task is a challenge (D).

So here we have a longer chain link through the premises, -B > C > D and a conclusion that states A > D. Thus, we must link A to D to assure that the conclusion comes logically. We can do that by finding an answer choice that says A > -B. This is answer choice C: Trust Others (A) > (Not) Believe Others (-B).

Finally, through diagramming this stimulus, the question became very easy. However, Powerscore generally advises to not diagram on the test. How would I reconcile these two realities? I will note that I missed this question on my practice test, using almost 1 min 30 seconds. Upon review, however, I completed it correctly.

[Jeff Wren]

Hi Roadto170,

Your understanding of the stimulus and your diagram look good (assuming the ">" symbol is shorthand for a conditional arrow).

I was rather surprised by your statement, "However, Powerscore generally advises to not diagram on the test. " That is certainly not how I'd describe our approach to conditional reasoning. We spend a fair amount of time teaching exactly how to diagram conditional reasoning. In fact, if you look at the prior explanations for this question by Dave, Nikki, and Rachael, they all include diagrams.

There is a good discussion of whether or not (i.e. when) to diagram conditional reasoning in "The Logical Reasoning Bible." I'm guessing that if you read this discussion, you may have gotten the wrong idea. For example, it is true that "most problems do NOT need to be diagrammed" for test takers who are well-versed/practiced in conditional reasoning. However, it is never wrong to diagram conditional statements, and there are certain complex conditional arguments that almost everyone should diagram. Diagramming is a tool, so use it as necessary.

My general advice is to start by diagramming every conditional statement that you come across in LR (and take the contrapositive too, while you're at it). These are good habits to get into, provide good practice, and will help with your understanding of conditional reasoning. Later, after you've done a lot of practice and really have the hang of it, you can start backing off of diagramming every conditional statement/contrapositive.

As a rule of thumb, if you ever miss an LR question with conditional reasoning and you didn't diagram it, then you should have diagrammed it. It is far better to take a little extra time to diagram and get the question correct than to try to do it in your head to save a few seconds and get it wrong.

Personally, I prefer to diagram anything beyond one or two fairly simple conditional statements. Even though I could do most of the questions in my head, I prefer to see it on paper (I'm a very visual person), and I find that I'm less likely to make errors this way.

Finally, when students complain that diagramming takes too long, my response is that is because they aren't good at it and the reason that they aren't good at it is that they haven't practiced enough. With sufficient practice, diagramming takes very little time. You should be really able to read and diagram without hesitating by test day.