At a large elementary school researchers studied a small group of children who successfully completed an experimental...

Sam on July 24 at 04:25AM

Why C over B?

Why not B?

1 Reply

Ravi on July 24 at 04:54AM

@samxinghaoli,

Happy to help. Let's look at (B) and (C).

We're looking for the answer choice that weakens the argument.

(B) says, "Those children who began the program but who did not
successfully complete it had lower preprogram levels of achievement
than did those who eventually did successfully complete the program."

This is a tempting answer choice, but the conclusion of the argument
didn't compare the levels of achievement between those folks who
completed the program and those who didn't. Rather, the conclusion was
based on the increase in achievement observed in those who actually
finished the program. Whether or not this group started really low or
really high does not matter, as the premises informed us that they
still experienced an increase in their achievement. Thus, (B) doesn't
weaken the argument, so it's out.

(C) says, "Many of the children who completed the program subsequently
sought membership on a school chess team that required a high grade
average for membership."

(C) provides us with an alternative cause for why those who finished
the program performed better in school. They performed better because
they became more concerned with doing well in school, as they had
added motivation to perform better because of the high grade point
average required for the team membership. Thus, it's possible that the
extra motivation and hard work caused these people to perform better
in school, rather than the skills they acquired playing chess. Thus,
(C) weakens the argument and is the correct answer choice.

Does this make sense? Let us know if you have any more questions!