Observational Study vs Experiment

Researchers are investigating if girls type faster than boys. They record how long it takes for a SRS of 20 boys and 20 girls to type 500 words and compare the averages.

• Survey

• Observational Study

• Experiment

A school wants to know what percent of their students ride the bus home. The bus drivers as asked to count the number of students they drive one day.

• Survey

• Observational Study

• Experiment

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

• Observational Study

• Experiment

You want to see if students who have a 4.0 grade point average study more than those who do not.

• experiment

• observational study

In an ________________, a researcher observes and measures characteristics of interest of part of the population but does not change existing conditions.

• Experiment

• Observational Study

Individuals are observed and variables are measured without controlling the individuals or the environment

• population

• observational study

• experiment

• secondary data

Individuals are monitored for measures of variables of interest but not influenced in response.

• Observational Study

• Experiment

• Voluntary Response

• Single-Blind

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

Which of the following is a key distinction between well designed experiments and observational studies?

• More subjects are available for experiments than for observational studies.

• Ethical constraints prevent large-scale observational studies.

• Experiments are less costly to conduct than observational studies.

• An experiment can show a direct cause-and-effect relationship, whereas an observational study cannot.

• Tests of significance cannot be used on data collected from an observational study.

You look at data to see if students who have a 4.0 grade point average study more than those who do not.

• experiment

• observational study