Logical reasoning PrepTest 129 · Section 3 · Question 18

Incorrect. Since the conclusion is about the therapists and types of therapy they practice, the specific techniques they use are out of scope. The argument establishes that the therapies are different, so even if they're only different in how they use the same techniques, the argument still works.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Errors in Reasoning

Stimulus Summary:
Study: Patients sent to psychotherapists practicing new therapy progressed more than those sent to psychotherapists practicing traditional therapy.Conclusion: Those practicing the new therapy are more effective.

Answer Anticipation:
This argument starts by mentioning a study, so we should start by considering a sampling flaw. In this case, is the sample large and representative/randomly assigned between the groups? There's no reason to question the size of the sample, but there is reason to believe that the sample might not be representative because the patients weren't randomly assigned!

The argument looks at patients referred by their doctors to psychotherapists practicing two types of psychotherapy, but there's no indication how these patients were referred. It's possible that doctors tend to send easier to treat patients to the psychotherapists practicing the new therapy, whereas they send the harder cases to those practicing traditional therapy. Since the sample wasn't randomly assigned, there was no controlling for this factor, and thus the sample was flawed.

Note that there was another potential flaw here, since the argument is about psychotherapists and psychotherapy. If the argument concluded something about the forms of therapy, then the argument would be flawed because it might have been the therapists and not the therapy determining outcomes. However, the conclusion is about the effectiveness of the therapists practicing the types of therapy, so this flaw isn't present.

Answer Explanation:
This answer brings up a possibility that would mean the sample for the study was skewed. If the patients referred to each type of therapist are different from each other, then the study can't lead to conclusions about the effectiveness of the therapists, as the patients may be what is determining the outcomes.

Key Takeaway:
Whenever a study is done, your first consideration should be whether a sampling flaw is present. The sample has to be large and representative/randomly assigned. If the groups aren't split randomly, then the answer will likely highlight that the two groups could have a difference relevant to the conclusion.

Incorrect. Whether or not these psychotherapists are trained in both forms of therapy, they're practicing specific forms of it, so this answer is out of scope.

Incorrect. It doesn't ignore this possibility since the conclusion is about the therapists and not the therapy. The conclusion is just that one type of therapist is more effective than another—whether that's because of the type of therapy they use or some inherent personality attribute that led them to practice a certain type of therapy, the conclusion still holds.

Incorrect. Again, by focusing the conclusion on the therapists and not the type of therapy, the conclusion considers it possible that some personality trait of the therapist is responsible for the effectiveness instead of the type of treatment they're implementing.