Students take a pretest that assesses their math skills. Those who receive low s
ID: 3208850 • Letter: S
Question
Students take a pretest that assesses their math skills. Those who receive low scores are given the opportunity to take three one-hour refresher sessions designed to review the basic math skills needed for the statistics course. Those who took the refresher sessions performed worse than those who did not on the final exam in the statistics course. Can you conclude that the refresher course has a negative impact on performance in the statistics course?
Explain your answer. Also provide a plausible alternative explanation for the association between variables
Explanation / Answer
We cannot conclude that the refresher course hhas a negaive impact on the peformance in the statistics course.
EXPLANATION:
Let X = performance in the statistics course
Y = refresher course.
Suppose we get negative correletion coefficient between X and Y, we cannot conclusde that X and Y are negatively correlated.
REASON: X and Y may each may be related to a third variable Z, which in turn will affect the relation between X and Y.
EXAMPLE:
Let Z = Preoccupation of the students in some cultural activities just before exam, students unwell at the time of examination, political unrest at the time of refresher sessions, etc.
Possible solution: While studying the correlation between X and Y, other related things should be maintained constant. Then only, the result arrived at will be meaningful.