Editorial: A proposed new law would limit elementary school class sizes to a maximum of 20 students. Most parents su...

Nivens on February 21, 2020

Why D?

Can you explain this?


Shunhe on February 21, 2020

Hi @nivensdc,

Thanks for the question! So we have two arguments happening here. The first argument is the parents’ argument. The parents are saying that class sizes should be limited. Why? Because smaller class sizes let teachers devote more time to each student, and as a result, students will become more engaged in the learning process. In other words

TDMTS (teachers devote more time to student) —> MELP (more engaged in learning process)

The second argument is the one we’re concerned about, the researchers’ argument. The researchers say that the parents’ reasoning is questionable. Why? Because actually, their studies have shown that schools with smaller class sizes, though they did have teachers devote more time to each student, the students’ average grades were unchanged. If there’s a relation between the students’ average grades and the students’ engagement in the learning process, then the parents’ reasoning is faulty, since you would have a sufficient condition without the necessary condition.

However, note what this assumes. It assumes, of course, that there IS some kind of correlation between the average grades and the engagement in the learning process. Let’s negate this assumption. If there isn’t a good correlation between these two things, then the researchers’ argument falls apart, because teachers devoting more time to their students could be consistent both with more engaged students and grades not increasing. Thus, (D), which provides this assumption, is the correct answer.

Hope this helps! Feel free to ask any other questions that you might have.