Independent vs. Dependent Variable Warm Up

A psychologist designed a study to test the effects of cell phone use on driving safety. Participants were randomly assigned either to drive an automobile simulator while talking to a friend on a cell phone or to drive a simulator without talking on a phone.

In the study, cell phone use can be described as

• a dependent variable

• an independent variable

Answer explanation

The researcher is manipulating the change in cell phone use because they tell one group to use a cell phone while driving and the other group to not use a cell phone while driving. Since the researcher is manipulating the change of cell phone use, cell phone use is the independent variable. The dependent variable (what the researcher is measuring) is driving safety.

A research group involved with advertising is conducting a study to investigate whether shoppers are more likely to engage in impulse buying at the checkout than at any other place in the store. To do this, they randomly assign participants to spend 5 minutes near a checkout or 5 minutes in other areas of the store. They place impulse items in both areas and then count how many items each person puts into their cart.

In this study, the number of items people put in their carts is

• a dependent variable

• an independent variable

Answer explanation

In this study, the researcher is manipulating where the participants go in the store (so that is the IV). They are measuring impulse buying (which they've defined as the number of impulse items people put in their cart), so impulse buying is the dependent variable.

Researchers conducted a study in which 10 participants went to a laboratory around dinner time. The researcher assigned students to one of two groups by flipping a coin. Half of the participants were assigned to a “large bowl” group, and half were assigned to a “small bowl” group. By luck of the draw, 4 men and 1 woman were in the “large bowl” group, and 4 women and 1 man were in the “small bowl” group. Participants were told they could take as much pasta as they wanted from a serving bowl in the middle of the table, which was kept at a nearly full level. Participants were encouraged to go back for as many helpings of pasta as they wanted. In order to determine how much food each participant actually ate, the researchers measured the weight of the food that each participant took, as well as the amount that the participants left in their bowls.

What is the independent variable in this study?

Answer explanation

Since the researchers were controlling which bowl participants got, bowl size is the independent variable.

Since the researchers were measuring how much pasta participants took, that was the dependent variable.

A study was conducted to investigate the role of framing on concern for healthy eating. Each participant (N = 100) was randomly assigned to one of two conditions. In the first condition, the participants read an article indicating that obesity is a disease. Participants in the second condition read an article indicating that obesity is the result of personal behaviors and decisions.

Participants were then asked to indicate how important it would be for them to eat a healthy diet. Scores ranged from 1 (not very important) to 9 (very important).

In this study, what is the dependent variable?

Answer explanation

Since the researchers are measuring participants' ratings, that is the dependent variable.

Since the researchers are controlling the article participants read, that is the independent variable.

When experimenting with the growth of a plant, a scientist uses three (of the same type of) plants, two different fertilizers, equal light, and equal water. What type of variable is the fertilizer?

• Dependent
• Independent
• Control
• Compound

Students took a test after they had studied either in silence or with the television turned on. What is the dependent variable?

• subject

• test scores

• silence

• amount of exposure to television

Individuals will respond more to a person in uniform than to a person not in uniform. What is the independent variable?

• individuals

• person in uniform

• response to uniform

• none of these work

This is a method of research where an investigator manipulates one or more factors (independent variables) to observe the effect on some behavior or mental process (the dependent variable).

• Experiments
• Case Study
• Survey
• Observational
• Correlational

In a study of the effect of a driver training program on driving skill, a possible operationalisation of the dependent variable would be...

• driving quality
• number of accidents
• hours spent training
• amount of traffic

Factors that cause differences between the experimental group and control group other than the independent variable. 

• control group
• population
• confounding variables

Tags

NGSS.MS-PS2-5