A study was conducted to compare five new textbooks. Thirty teachers were asked to rate the textbooks they used in the previous semester, and then they were randomly assigned to one of five new textbook groups (n = 6). At the end of the semester, teachers' ratings of the new textbooks (Y) were collected. What may be an appropriate covariate for this study?
A) Students' achievement at the end of the semester.
B) Students' rating of the new textbook at the end of the semester.
C) Teachers' rating of the old textbook.
D) Teachers' ethnicity.

Question

Quizplus · Accepted Answer

Teachers' rating of the old textbook could serve as an appropriate covariate because it provides a baseline measure of the teachers' perceptions or biases towards textbooks in general, which can be controlled for when analyzing the effect of the new textbooks on their ratings. This helps in isolating the effect of the new textbooks from teachers' inherent rating tendencies.

A Study Was Conducted to Compare Five New Textbooks