Reporter: A team of scientists has recently devised a new test that for the first time accurately diagnoses autism i...

Meredith on October 28, 2019

Explanation Please

Why is B correct and A & E wrong?


on October 31, 2019

Hello @Meredith,

Here is the problem with A. The new test may not be the first intended for diagnosing autism at an early age. Rather, it is the first test to do so accurately. The argument doesn't depend on it being the first ever.

E is incorrect, because we are not talking about the age at which autism can have an effect. We are only talking about diagnosis at an early age. There could have been plenty of evidence beforehand that autism affects young children, and that does not impact the argument.

Let's take a closer look at the conclusion. "Autistic children can therefore now benefit much earlier in life than before from the treatments already available." We know that there is still a problem with the new test. It had 2 false positives. This leaves a hole in the argument. Is it still a valid test on which to base treatment decisions? If not, the conclusion cannot be properly drawn. B answers this question, confirming that the test can be used even with some false positives. This is the necessary assumption.

on June 16, 2020

Can you explain why D wouldn't work?

on January 6, 2021

D is a trap answer. While it does apply to that second to the last sentence it is not a necessary assumption of the premise and its conclusion. The premise concludes that because this test identified 10 children with the addition of 2 false identifications, children as a whole will benefit from this test. The conclusion is essential that those mistakes won't impact the tests ability to identify and provide proper treatment to the correctly identified children. D is wrong because it focuses on the negative implications of the two wrongly identified kids, whereas the premise is more concerned with the benefit to the correctly identified kids. If the correctly identified children won't benefit earlier in life because the test is incorrectly determining children to be autistic, then the whole conclusion collapses. Essentially "A diagnostic test that sometimes falsely gives a positive diagnosis CANNOT still provide a reasonable basis for treatment decisions" collapses this whole premise's conclusion.