Observational study vs. Experiment WS

Observational study vs. Experiment

Practice worksheet

Observational Study

The researcher doesn't choose what happens to the subject, sits back, observes, and gathers information.

Two types of Observational Study

• Retrospective: Study events from the past such as medical records.

• Prospective: Chooses subject before then study events for the future.

Experiment

The researcher chooses what happens to the subject. Subjects actively participate as the researcher requires.

Components of an Experiment

• Subject: who or what is being studied

• Treatments: conditions assigned to the subject

• Response: what is measured at the end of the experiment 

Multiple Choice

A marketing firm conducts a study where 200 people are shown either a 30 second animated commercial or a 30 second live action commercial for the same product. After viewing the commercial, subjects are asked to rate the product ‘1’ to ’10.’

• Experiment

• Observational Study

Multiple Choice

Cause and effect (causation) can only be proven with EXPERIMENTS.

• True

• False

Multiple Choice

350 athletes who had suffered hamstring injuries were randomly assigned to one of two different exercise programs. The first group is assigned to a static stretching program and the second group is assigned to an agility and trunk stabilization program. The researchers recorded how long it took the athletes to return to sports. What is the SUBJECT?

• Duration of the return

• Two different exercise programs

• 350 athletes

Multiple Choice

350 athletes who had suffered hamstring injuries were randomly assigned to one of two different exercise programs. The first group is assigned to a static stretching program and the second group is assigned to an agility and trunk stabilization program. The researchers recorded how long it took the athletes to return to sports. What are the treatments?

• Duration of the return

• Two different exercise programs

• 350 athletes

Multiple Choice

350 athletes who had suffered hamstring injuries were randomly assigned to one of two different exercise programs. The first group is assigned to a static stretching program and the second group is assigned to an agility and trunk stabilization program. The researchers recorded how long it took the athletes to return to sports. What is the response?

• Duration of the return

• Two different exercise programs

• 350 athletes

Multiple Choice

Partners Healthcare, a medical research firm, looks at a database of patient medical records from 1971-1980 and 1991-2000. Using these medical records, Partners Healthcare compares the association between heart disease and diabetes in the 1970’s to the same association in the 1990’s. They conclude that this association has weakened over time.

• Observational study: Prospective

• Observational study: Retrospective

• Experiment

Multiple Choice

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

Multiple Choice

One group of subjects was given an herbal supplement and another group was given a placebo. After one year, the number of illnesses each group had was compared.

• Observational Study

• Experiment

Multiple Choice

A marketing firm conducts a study where 200 people are shown either a 30 second animated commercial or a 30 second live action commercial for the same product. After viewing the commercial, subjects are asked to rate the product ‘1’ to ’10.’ What is the SUBJECT in this experiment.

• 200 people

• Animated and Live action commercials

• Rating the product

Multiple Choice

A marketing firm conducts a study where 200 people are shown either a 30 second animated commercial or a 30 second live action commercial for the same product. After viewing the commercial, subjects are asked to rate the product ‘1’ to ’10.’ What is the RESPONSE in this experiment.

• 200 people

• Animated and Live action commercials

• Rating the product

Multiple Choice

A marketing firm conducts a study where 200 people are shown either a 30 second animated commercial or a 30 second live action commercial for the same product. After viewing the commercial, subjects are asked to rate the product ‘1’ to ’10.’ What are the TREATMENTS in this experiment.

• 200 people

• Animated and Live action commercials

• Rating the product

Multiple Choice

One group of subjects was given an herbal supplement and another group was given a placebo. After one year, the number of illnesses each group had was compared. What is the response variable?

• herbal supplement/placebo

• number of illnesses