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

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

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

Does lack of sleep affect your academic performance? A student explores this question by asking everyone in his statistics class to write down on a piece of paper his or her score on a recent test and a total number of hours of sleep he or she got on the last three nights before taking the test.

• Observational Study

• Experiment

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

• Observational Study

• Experiment

• Voluntary Response

• Single-Blind

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

• population

• observational study

• experiment

• secondary data

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

• Experiment

• Observational Study

Which scenario is best described as an observational study?

• For a class project, students in Health class ask every 10^th student entering the school if they eat breakfast in the morning

• A social researcher wants to learn whether or not there is a link between attendance and grades. She gathers data from 15 school districts

• A researcher wants to learn whether or not there is a link between children’s daily amount of physical activity and their overall energy level. During lunch at the local high school, she distributed a short questionnaire to students in the cafeteria

• Sixty seniors taking a course in Advanced Algebra Concepts are randomly divided into two classes. One class uses a graphing calculator all the time, and the other class never uses graphing calculators. A guidance counselor wants to determine whether there is a link between graphing calculator use and students’ final exam grades

A football coach thinks lessons in yoga will improve the flexibility of his players and thereby reduce injuries. To test his theory, he randomly divides the players on the team into two groups. One group has 45 minutes of yoga training each day. The players in the other group do the standard stretching routine the team has used in the past. He compares flexibility in the two groups at the end.

• Observational Study

• 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