1. Education
You can opt-out at any time. Please refer to our privacy policy for contact information.

What Is a Dependent Variable?

By

The dependent variable can change due to manipulations to the independent variable.

In psychology experiments, researchers look at whether changes to the independent variable lead to changes in the dependent variable.

Image: Spiritia / Wikimedia Commons

Definition:

The dependent variable is the variable that is being measured in an experiment. For example, in a study looking at how tutoring impacts test scores, the dependent variable would be the participants' test scores.

In a psychology experiment, researchers are looking at how changes in the independent variable cause changes in the dependent variable.

Observations About the Dependent Variable

  • "In psychology studies, the dependent variable is usually a measurement of some aspect of the participants' behavior. The independent variable is called independent because it is free to be varied by the experimenter. The dependent variable is called dependent because it is thought to depend (at least in part) on the manipulations of the independent variable."
    (Weiten, 2013)

  • "One criterion for a good dependent variable is stability. When an experiment is repeated exactly - same subject, same levels of independent variable, and so on - the dependent variable should yield the same score as it did previously. Instability can occur because of some deficit in the way we measure some dependent variable. Assume that we wish to measure the weight in grams of an object - say, a candle - before and after it is lit for 15 minutes. We use a scale that works by having a spring move a pointer. The spring contracts when it is cold and expands when it is hot. As long as our weight measurements are taken at constant temperatures, they will be reliable. But if temperature varies while objects are being weighed, the same object will yield different readings. Our dependent variable lacks stability."
    (Kantowitz, Roediger, & Elmes, 2009)

Examples of Dependent Variables

  • Researchers want to discover if listening to classical music helps students earn better grades on a math exam. In this example, the scores on the math exams are the dependent variable.

  • Researchers are interested in seeing how long it takes people to respond to different sounds. In this example, the length of time it takes participants to respond to a sound is the dependent variable.

  • Researchers want to know whether first-born children learn to speak at a younger age than second-born children. In this example, the dependent variable is the age at which the child learns to speak.

More Psychology Definitions: The Psychology Dictionary

Browse the Psychology Dictionary

A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z |

References

Kantowitz, B. H., Roediger, H. L., & Elmes, D. G. (2009). Experimental psychology. Belmont, CA: Wadsworth.

Weiten, W. (2013). Psychology: Themes and variations, 9th ed. Belmont, CA: Wadsworth.

©2014 About.com. All rights reserved.