Question

Kalim wants to study the effectiveness of a new teaching method. He includes two teachers of a class in the experiment. One teacher uses the new method of teaching, and the other teacher uses the old method. At the end of the semester, he finds that students who were taught in the new way had higher grades than students taught in the old way. What is the confounding variable?

Answer 1

The answer is the two teachers.

Step-by-step explanation:

In this example, it's possible that the students had higher grades because of different factors, most likely the other teacher's personality. If the experiment was to be truly effective and valid, Kalim should have used the same teacher for both methods. This is an important factor for ensuring research validity.