Question

1.31 light and exam performance: a study is designed to test the effect of light level on exam performance of students. the researcher believes that light levels might have different effects on males and females, so wants to make sure both are equally represented in each treatment. the treatments are fluorescent overhead lighting, yellow overhead lighting, no overhead lighting (only desk lamps). a) what is the response variable? light level sex fluorescent overhead lighting no overhead lighting exam performance b) what is the explanatory variable? fluorescent overhead lighting light level no overhead lighting exam performance sex c) what is the blocking variable? exam performance no overhead lighting sex light level fluorescent overhead lighting

Explanation:

• a) The response variable is what is being measured as an outcome. Here, the study aims to see the effect on exam performance, so it is the response variable.
• b) The explanatory variable is what is thought to influence the response. Light level is being manipulated to see its effect on exam performance, so it is the explanatory variable.
• c) The blocking variable is used to control for variability. Since the researcher believes light levels may affect males and females differently and wants equal representation of each in treatments, sex is the blocking variable.

Answer:

a) exam performance
b) light level
c) sex