In order to reduce classroom overcrowding

[BTGmoderatorDC]

In order to reduce classroom overcrowding while maintaining academic standards,
Omega High School last year tested an online physics course with twenty volunteers
from the senior class. Although they met with the teacher once a week for lab work,
the students attended all lectures and did all their homework via remote computer.
All of the students in the online physics course easily passed the statewide physics
exam at the end of the school year. Administrators at the high school concluded from
this test that all students can learn effectively outside the classroom and decided that
Omega High School should offer all of its science courses online.

A. The science classrooms currently in use are bigger than the classrooms used for
other subjects.

B. The students who took the online physics course had access to the same science
library reference materials as the physics students who did not take the class online.

C. Omega High School has received a grant to purchase new computers for the next school year.

D. The students who enrolled in the online physics course were more self-motivated
than most students and were high achievers in the top ten percentile of their class.

E. There are excellent computer programs for teaching high school earth science,
biology and chemistry.

Which of the following, if true, would cast the most doubt on the conclusion drawn above? Can some experts help me find the best Option in this?

OA D

[DavidG@VeritasPrep]

In order to reduce classroom overcrowding while maintaining academic standards,
Omega High School last year tested an online physics course with twenty volunteers
from the senior class. Although they met with the teacher once a week for lab work,
the students attended all lectures and did all their homework via remote computer.
All of the students in the online physics course easily passed the statewide physics
exam at the end of the school year. Administrators at the high school concluded from
this test that all students can learn effectively outside the classroom and decided that
Omega High School should offer all of its science courses online.

A. The science classrooms currently in use are bigger than the classrooms used for
other subjects.

B. The students who took the online physics course had access to the same science
library reference materials as the physics students who did not take the class online.

C. Omega High School has received a grant to purchase new computers for the next school year.

D. The students who enrolled in the online physics course were more self-motivated
than most students and were high achievers in the top ten percentile of their class.

E. There are excellent computer programs for teaching high school earth science,
biology and chemistry.

Which of the following, if true, would cast the most doubt on the conclusion drawn above? Can some experts help me find the best Option in this?

OA D

This is a causality argument. The conclusion is that the online class caused the students to pass the statewide exam. In condensed form:

Taking online class ---> pass exam

One way to weaken the argument is to find an alternative cause that could account for why all the students in the online class passed their exam. Say, for example, that because everyone in the online class volunteered to do so, this population of students was more motivated than students in a random sample would have been. This is what D gives us. If the students in this class were unusually motivated, then there's no reason to believe that this performance could be duplicated in an online class in which the participants were not self-selecting.