Logical reasoning PrepTest 144 · Section 4 · Question 21

Incorrect. Without knowing if these students saw an increase in achievement levels, we can't determine what impact these students have on the conclusion.

Incorrect. The pre-program levels of achievement are only relevant inasmuch as they allow a conclusion to be drawn that the post-program levels of achievement are higher. Since the argument doesn't rely on the students who completed the program having higher than average levels of achievement—just higher than they started with—the relative level of starting achievement is out of scope.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Weaken

Stimulus Summary:
Sample Ð Students who completed a chess program
Results Ð Most of them saw their grades improve significantly across the board
Conclusion Ð Chess skills (reasoning power/spatial intuition) lead to intellectual achievement elsewhere

Answer Anticipation:
Whenever a study is done, we should start by considering two flaws: sampling, and correlation/causation.

Here, the sample is students who completed a chess program. It's noted that this was a "small" group, and "most" of them saw a jump in grades afterwards. There are a few issues there. First, the sample was notably "small," and second, it didn't look at those who didn't go through the program to look at their grades. Second, the group wasn't randomly assigned—to be a valid study, the students couldn't "self-select" into the program. The benefits also weren't universal, which we'll get to in the second flaw. In any case, this study wasn't set up in a way that leads the sample to be necessarily representative, so answers that point this out can weaken the argument.

Second, correlation/causation. The jump in grades was correlated with successful completion of the program, and the stimulus even notes that the timeline works out—the effect was seen "soon" after the chess program ended. However, that's not enough to show that the chess program caused the jump in grades, let alone that one specific aspect of the chess program (reasoning power, spatial intuition) was the cause. Especially since the improved grades weren't seen by all of the students. Since there's a correlation/causation flaw here, we can weaken it with the common answers:

(1) ID an alternative cause of the increased intellectual achievement
(2) Bring up counterexamples (e.g., students who weren't in the chess program also saw an increase in their grades)
(3) Support the reverse causality (though, as noted, the timeline prevents this from being a viable answer as the grade increase happened after the chess program ended)

That's a lot to be on the lookout for, and these answers look long, so let's head into them and get to work!

Answer Explanation:
This answer suggests an alternative cause for the increase in achievement. It wasn't that the students developed stronger reasoning power and spatial intuition leading to higher achievement, it's that they enjoyed chess and wanted to be on the chess team, requiring them to get good grades. This answer provides motivation to improve grades outside of the cause assumed in the conclusion, and so it weakens the argument.

Key Takeaway:
For correlation/causation flaws, it's really important to focus on the specifics of the causal relationship. Here, the supposed cause wasn't chess but certain skills exercised in chess. Mixing that up would make it particularly difficult to find the correct answer.

Incorrect. If the students in this program were also in the chess program, then this would suggest an alternative cause that would weaken the argument. However, since these students were not in the chess program, this answer doesn't affect the argument since the argument doesn't assume that the chess program is the only program that would have a positive impact on students (in fact, it suggests any program that improves reasoning power and spatial intuition would have a similar effect).

Incorrect. This answer is interesting—it suggests that these students did have the assumed cause in that they're good chess players and so likely have the qualities exercised in chess. However, without knowing what effect this has had on their grades—are they generally high achievers? did they see an improvement in grades while learning to play chess?—it doesn't actually impact the argument.