A recent clinical study demonstrated a possible connection between coffee consumption and heart health. The researchers performed a 6-week trial with 191 individuals, all of whom were heavy coffee drinkers (average of 5 cups/day) prior to the experiment, but none of whom were smokers. They divided the 191 participants into three groups: no coffee consumption, 1-3 cups/day, and 4 or more cups/day. They measured blood levels of cholesterol and homocysteine as indicators of heart health. Only the no-coffee group showed a significant drop in both indicators. Previous studies had demonstrated that decreases of the magnitude observed in the no-coffee group could cut the incidence of heart disease by 10-15%.
a) What is the problem/question being studied?
b) What is the hypothesis?
c) What is the experimental variable?
d) List the controls.
e) What is being measured to test the hypothesis?