Experiment vs. Observational Study

Compare voter satisfaction levels between people assigned to use either paper ballots or touchscreen machines.

• Experiment
• Observational Study

Determine which brands of orange juice people prefer. The people are randomly chosen at the supermarket and are asked to taste both brands without knowing which brand they are drinking.

• Experiment
• Observational Study

Determine if people who take vitamin C every day are less likely to get colds.

• Experiment
• Observational Study

Compare the grades on a final math test of 25 students who use calculators and 25 students who do not use calculators. The students decide which group they are in.

• Experiment
• Observational Study

A teacher asks her students to write down all they eat in a day and then calculate the total number of calories consumed. 

• Experiment
• Observational Study

The cafeteria manager of a high school wants to find out if high prices are keeping students from using the cafeteria. Fifty students are chosen at random to receive half-price lunch passes every day for a month. The manager then records the number of passes used. 

• Experiment
• Observational Study