Daniel would like to study a new way of teaching research methods. There are two sections of research methods being taught at 2pm on Mondays and Wednesdays, so Daniel has one teacher use the new way and the other teacher use the old way. At the end of the semester, he finds that students who were taught the new way had higher grades than students taught the old way. What is the extraneous variable?
a. grades at the end of the semester
b. method of instruction (new versus old)
c. the two teachers
d. There is no extraneous variable in this study.
