Observational and Experimental studies

A study in which the researcher simply watches the subjects or asks questions but does not impose any sort of treatment.

• observational

• experimental

Tags

CCSS.HSS.IC.B.3

A controlled study in which the researcher attempts to understand cause and effect relationships. The study is controlled in the sense that the researcher controls how subjects are assigned to groups and which treatments each group receives

• observational

• experimental

Tags

CCSS.HSS.IC.B.3

What kind of study is this?

A researcher wants to determine if there is a relationship between attending an ACT prep class and scores achieved on the ACT exam. A group of students who took the ACT are surveyed. The scores from the students who took the prep class are compared with the scores of those who did not take the prep class.

• observational

• experimental

Tags

CCSS.HSS.IC.B.3

What kind of study is this?

A researcher wants to determine if the color of a basketball influences the number of times a shooter makes a basket. A random group of students is chosen and asked to shoot a series of baskets using a normal regulation basketball. The data is recorded. The same group is then given a blue colored basketball and the same number of shots is repeated. The data is again recorded and analyzed.

• observational

• experimental

Tags

CCSS.HSS.IC.B.3

What kind of study is this?

You get a list of all students in your classes and use a random number generator to select 30 of them. You take these students' blood pressure and then have them fill out a questionnaire about how much exercise they get to determine if exercise has an effect on blood pressure.

• observational

• experimental

Tags

CCSS.HSS.IC.B.3

What kind of study is this?

A study to determine whether taking aspirin regularly helps to prevent heart attacks. A large group of male physicians of comparable health were randomly assigned equally to taking an aspirin every second day or to taking a placebo. After several years, the proportion of the study participants who had suffered heart attacks in each group was compared.

• observational

• experimental

What kind of study is this?

Subjects were randomly assigned to two groups. One group was given a new medicine and the other group was given a placebo. After 6 months, the number of infections in each group was compared.

• observational

• experimental

What kind of study is this?

A researcher finds that people who are more hostile have higher total cholesterol levels than those who are less hostile.

• observational

• experimental

What kind of study is this?

A researcher stood at a busy intersection to see if the color of the car that a person drives is related to running red lights.

• observational

• experimental

What kind of study is this?

Subjects are randomly assigned to four groups. Each group is placed on one of four different diets. After six months, the blood pressures of the groups are compared to see if diet has any effect on blood pressure.

• observational

• experimental