Keb Is Convinced That Teachers Provide More Praise to Their

Multiple Choice

Keb is convinced that teachers provide more praise to their students while he is observing in their classrooms than they do otherwise. Of the following the most appropriate way to decrease Keb's concerns and increase validity of his data is

A) to tell teachers he is interested in something unrelated to praise.
B) to focus on a smaller number of teachers.
C) increase the amount of time he spends in the classrooms.
D) observe the classes covertly.