A school principal wants to observe if natural light has an

A school principal wants to observe if natural light has an effect in the classroom learning. The principal randomly chooses two groups of students of the same age and grade, and places both groups in rooms on opposite sides of the school, one facing east and one facing west, during a 10 am class. The test scores of both classes are compared at the end of the semester. How could this observation be changed into a valid experiment of the effects of natural light? A. by including classrooms facing north and south B. by introducing adjustable light fixtures in each classroom C. by tinting the windows in both classrooms with the same film D. by introducing adjustable blinds in each classroom

Solution

The observation (that is whether natural light has an effect on classroom) can be changed into a valid experiment of the effects of natural light by: