A Study Was Conducted to Look at Whether Caffeine Improves

Multiple Choice

A study was conducted to look at whether caffeine improves productivity at work in different conditions. There were two independent variables. The first independent variable was email, which had two levels: 'email access' and 'no email access'. The second independent variable was caffeine, which also had two levels: 'caffeinated drink' and 'decaffeinated drink'. Different participants took part in each condition. Productivity was recorded at the end of the day on a scale of 0 (I may as well have stayed in bed) to 20 (wow! I got enough work done today to last all year) .
- Looking at the group means in the table below, which of the following statements best describes the data? $$\begin{array} { | l | l | l | } \hline & \text { Decaffeinated Drink } & \text { Caffeinated Drink } \\\hline \text { No Email } & 12.08 & 19.83 \\\hline \text { Email } & 11.98 & 5.49 \\\hline\end{array}$$

A) There is likely to be a significant main effect of caffeine.
B) A significant interaction effect is likely to be present between caffeine consumption and email access.
C) The effect of email is relatively unaffected by whether the drink was caffeinated.
D) The effect of caffeine is about the same regardless of whether the person had email access.