04.03- Observational vs Experimental

To test the effects of breakfast on grades I ask my students if they ate breakfast and then compare the breakfast eaters grades to the non-breakfast eaters.

This is an example of:

• Observational study

• Experiment

Identify each of the following as an observational study or an experiment.

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

• Observational study

• Experiment

All 200 fifth grades at a school are randomly assigned to one of two groups. One group studies addition of fractions with the aid of a calculator, the other studies the same topic without a calculator. Scores on a fractions test are compared after two weeks.

• Observational Study

• Experiment

A researcher stood at a school parking lot entrance to see if the color of a car is related to the driver not wearing a seatbelt.

• Observational Study

• Experiment

A professor finds that people who are obese have higher cholesterol levels than those who are not obese.

• Observational Study

• Experiment

A researcher is interested in learning how people use the neighborhood park. The researcher goes to the park daily for a month and records how many people are on the playground, how many are on the basketball court, how many are at the picnic tables, and how many are at the skate park. What type of study is this?

• Observational

• Experiment

Experiment or Observational Study?

A park employee wants to know if latex paint is more durable than non-latex paint. She paints 50 benches with latex paint, and 50 with non-latex paint then compares how much paint is remaining after 6 months.

• Experimental

• Observational

Explain whether the research topic is best addressed through an experiment or an observational study.

Does drinking alcohol while pregnant cause birth defects for a baby?

• Experimental

• Observational