Robert Rosenthal did a series of studies in which he carefully manipulated teachers' expectations of students; he did this by labeling children in different ways. The main concern in a controlled study of this sort is with:
A) External validity
B) Internal validity
C) Reliability
D) Effect sizes
E) b and c

Question

Quizplus · Accepted Answer

The main concern in this controlled study is with internal validity, as Rosenthal is manipulating one specific variable (teacher expectations) and needs to ensure that any observed differences in the labeled groups are actually due to that manipulation and not to other extraneous variables.

Robert Rosenthal Did a Series of Studies in Which He