1.33 Light, noise, and exam performance. A study is designed to test the effect of light level and noise level on exam performance of students. The researcher believes that light and noise levels might have different effects on males and females, so wants to make sure both are equally represented in each treatment. The light treatments considered are fluorescent overhead lighting, yellow overhead lighting, no overhead lighting (only desk lamps). The noise treatments considered are no noise, construction noise, and human chatter noise.
(a) What is the response variable?
The response, or dependent variable is the exam performance of students
(b) How many factors are considered in this study? Identify them, and describe their levels.
The factors considered in this study are light and noise treatments.
The levels for light treatments: fluorescent overhead lighting, yellow overhead lighting, and no overhead lighting - desk lamps only.
The levels for noise treatments: no noise, construction noise, and human chatter noise.
(c) What is the role of the sex variable in this study?
According to the study, males and females are both represented equally - so sex is a blocking variable in this study.
Blocking Example: Role of sex variable in the study