#22 - Only an expert in some branch of psychology could

[Alexandra Ruby]

Hi biskam,

You are on the right track and I think I understand your question. Hopefully, this response helps clarify.

The question stem is asking you what must be 100% true based on the information given in the stimulus. Thus, the other 4 incorrect answer choices could be false or are not necessarily true i.e. they could be 0-99% true.

Answer choices A, B and C could be false/not necessarily true because the stimulus does not give enough information to conclude that they must be 100% true. There is a possibility that they may be false or 0-99% true. We just do not know either way which renders those answer choices uncertain and, thus, incorrect in a Must Be True question.

If I misunderstood your question, please let me know!

[biskam]

I think it I got it. So for C ("Patrick is not certain of being able to devise a solution to his own behavioral problem"), this could be completely false/could be true, but we don't know if it's 100% MBT, which is what the correct answer is looking for.

So the possibilities of truth for C are:
1) it COULD be true that Patrick is not certain of being able to devise a solution to his own behavioral problem
2) it could be NOT true that Patrick is not certain of being able to devise a solution to his own behavioral problem, that is he could be true that he IS certain of being able to devise a solution to his own behavioral problem

I guess now I just don't see how option 2 could occur? How would he be certain of being able to devise a solution to his own problem?

[AthenaDalton]

Hi biskam,

The four incorrect answers for this question will be either "not necessarily true" or "must be false." So an answer that may or may not be true is an incorrect answer, and an answer that must be false is also an incorrect answer.

Based on the information in the stimulus, we don't know if Patrick will be able to solve his behavioral problem or not. We know that experts are never certain of being able to solve someone else's behavioral problems. However, we don't whether this rule applies to being able to solve one's own behavioral problems. We are also told that only an expert could solve Patrick's problem -- but we have no idea if Patrick is an expert or not.

So it's really impossible to say whether Patrick will be able to solve this one or not. Since we can't confirm with absolute certainty that Patrick "is not certain of being able to devise a solution" to his behavioral problem, answer choice (C) is an incorrect answer. Patrick might be categorically incapable of devising a solution to his problem. Or he might be an expert that has a fighting chance. We really don't know!

I hope clarifies things. Good luck!

[spearl04]

Hello,

I understand how to diagram the first sentence of the stimulus (U-->E), however, I am unsure of how to diagram the second sentence, which reads: "But no expert is certain of being able to solve someone else's problem." How can you tell which is the necessary condition and which is the sufficient condition?

Thank you!

[Robert Carroll]

spearl,

Any statement of the form "No person like this is able to do that" or "No thing with quality A possesses quality B" can be diagrammed as a conditional with the first part as the sufficient condition and the negation of the second part as the necessary condition. In this specific case, "No expert is certain of being able to solve someone else's problem" can be diagrammed thus:

expert certain of being able to solve someone else's problem

This is true because if I say that no expert can have that certainty, I'm also saying that anyone who IS an expert would have to LACK that certainty. So, "If you are an expert, you are not certain of being able to solve someone else's problem."

Note that the contrapositive would be:

certain expert

Because both the original conditional and the contrapositive say that BEING something (an expert, or certain) means you CAN'T be something else (certain or an expert respectively), this statement is saying that expertise and the relevant certainty are mutually exclusive. This could also be diagrammed using a Double-Not Arrow:

expert certain

which just means that you can't be an expert and have the certainty discussed at the same time.

Robert Carroll