dependent variable

[ dih-pen-duhnt vair-ee-uh-buhl ]
/ dɪˈpɛn dənt ˈvɛər i ə bəl /
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Mathematics. a variable in a functional relation whose value is determined by the values assumed by other variables in the relation, as y in the relation y = 3x2.Compare independent variable (def. 1).
Statistics. (in an experiment) the event studied and expected to change when the independent variable is changed.Compare independent variable (def. 2), control variable (def. 1).


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Origin of dependent variable

First recorded in 1850–55
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2022


What is a dependent variable?

In the context of scientific experiments, a dependent variable is the thing or situation being studied that you expect to change based on the choices you make during the experiment.

In general, a variable is called a variable because it can vary. It’s any factor that could change or be changed. In the context of scientific experiments, there are three different types of variables: dependent variables, independent variables, and control variables. Independent variables are the factors that you change to see how they affect the results. Dependent variables are things that are affected by the changes that you make—the results of the tests (which depend on the independent variables). Control variables are the factors that you do not change. They are kept the same for every test or measurement in order to make sure that the results can be compared fairly.

For example, let’s say you’re trying to figure out which brand of plant food will help a sunflower grow to the tallest height. The dependent variable is the final height of the sunflower. The independent variable (the factor that you change) is the brand of plant food. There are a number of other factors that could impact the growth of the plant, including things like the amount of sunlight and the amount of water. To allow for a proper comparison of the results, these need to be control variables—they need to be controlled, or kept the same. This way, you can have a greater degree of certainty that the final difference in heights (the dependent variable) is due to which food each sunflower received (the independent variable), not differences in sunlight or water.

Why are dependent variables important?

Science is messy. We like to think of experimentation as a simple process of “change one thing and record what happens,” but in reality, every possible subject of study has dozens of different factors that can impact the results. The dependent variable is the thing being impacted.

Scientists are trained to be careful when setting all the variables for an experiment. It’s important to keep track of the independent variables and control variables so you know why the dependent variable was affected in the way that it was.

Understanding the importance of variables will make you more likely to draw sound conclusions and less likely to fall for claims based on faulty science. For example, when examining suspicious statistics or experiment results, a good place to start is to ask what independent variables were involved—what was changed to get the dependent variable to change.

Did you know … ?

The term dependent variable is used in the context of formal scientific experiments, but you use the same concept all the time without thinking about it. The process of trial and error involves trying new methods of doing something until you get the results you want. The new methods are the independent variables and the results of each attempt are the dependent variables.

What are real-life examples of dependent variables?

Every experiment has a dependent variable, regardless of what is being studied. The dependent variable is the whole point of performing an experiment.


What other words are related to dependent variable?

Quiz yourself!

True or False? 

In an experiment, the dependent variable is the one that changes based on the different factors of the experiment.

How to use dependent variable in a sentence

British Dictionary definitions for dependent variable

dependent variable

a variable in a mathematical equation or statement whose value depends on that taken on by the independent variablein "y = f(x)", "y'"is the dependent variable
psychol statistics the variable measured by the experimenter. It is controlled by the value of the independent variable, of which it is an index
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for dependent variable

dependent variable
[ dĭ-pĕndənt ]

In mathematics, a variable whose value is determined by the value of an independent variable. For example, in the formula for the area of a circle, A = πr2, A is the dependent variable, as its value depends on the value of the radius (r). Compare independent variable.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.