Independent and dependent variables

In both math and science, dependent and independent variables can be plotted on the x and y axes of a graph. In experiments, you have to test one independent variable at a time in order to accurately understand how it impacts the dependent variable. You can also think of the independent variable as the cause and the dependent variable as the effect. You can use this typical form to determine the independent and dependent variables from the title of the study.

  • However, when comparing two different treatments, such as drug A and drug B, it’s usual to add another variable, called the control variable.
  • Independent and dependent variables are commonly taught in high school science classes.
  • If you didn’t have any constant variables, you wouldn’t be able to tell if the independent variable was what was really affecting the dependent variable.
  • You find some and conclude that gender identity influences brain responses to infant cries.

To ensure the internal validity of an experiment, you should only change one independent variable at a time. A true experiment requires you to randomly assign different levels of an independent variable to your participants. You can also apply multiple levels to find out how the independent variable affects the dependent variable. You measure the math skills of all participants using a standardized test and check whether they differ based on room temperature. An example is provided by the analysis of trend in sea level by Woodworth (1987). Here the dependent variable (and variable of most interest) was the annual mean sea level at a given location for which a series of yearly values were available.

So that the variable will be kept constant or monitored to try to minimize its effect on the experiment. Such variables may be designated as either a „controlled variable“, „control variable“, or „fixed variable“. Both the independent variable and dependent variable are examined in an experiment using the scientific method, so it’s important to know what they are and how to use them. In experiments, you manipulate independent variables directly to see how they affect your dependent variable. The independent variable is usually applied at different levels to see how the outcomes differ.

The control variable, which in this case is a placebo that contains the same inactive ingredients as the drugs, makes it possible to tell whether either drug actually affects blood pressure. In these studies, independent variables are still the grouping variables, what is the difference between deferred revenue and unearned revenue so key in on statements that indicate comparisons. The independent variable is the condition that you change in an experiment. It is called independent because its value does not depend on and is not affected by the state of any other variable in the experiment.

Introduction to Statistics

This helps you to have confidence that your dependent variable results come solely from the independent variable manipulation. The target variable is used in supervised learning algorithms but not in unsupervised learning. On the other hand, the value of a dependent variable is determined by some input, or independent variable.

  • A dependent variable is the variable being tested and measured in a scientific experiment.
  • Here are the definitions of independent and dependent variables, examples of each type, and tips for telling them apart and graphing them.
  • It is called the “dependent” variable because we are trying to figure out whether its value depends on the value of the independent variable.
  • The dependent variable (height) depends on the independent variable (age).
  • Note that any research methods that use non-random assignment are at risk for research biases like selection bias and sampling bias.

Boyle was then able to devise his equation based on his observations of the independent and dependent variables. The dependent variables are the things that the scientist focuses his or her observations on to see how they respond to the change made to the independent variable. If you have the variables in the wrong order, the sentence won’t make sense. The dependent variable is the condition that you measure in an experiment. You are assessing how it responds to a change in the independent variable, so you can think of it as depending on the independent variable.

Changes to each of these independent variables cause the dependent variables to change in the experiments. The independent variable (sometimes known as the manipulated variable) is the variable whose change isn’t affected by any other variable in the experiment. Either the scientist has to change the independent variable herself or it changes on its own; nothing else in the experiment affects or changes it.

Other variables

Of the two, it is always the dependent variable whose variation is being studied, by altering inputs, also known as regressors in a statistical context. In an experiment, any variable that can be attributed a value without attributing a value to any other variable is called an independent variable. Models and experiments test the effects that the independent variables have on the dependent variables. Sometimes, even if their influence is not of direct interest, independent variables may be included for other reasons, such as to account for their potential confounding effect. You have to be the one to change the popcorn and fertilizer brands in Experiments 1 and 2, and the ocean temperature in Experiment 3 cannot be significantly changed by other factors.

The independent and dependent variables are the two key variables in a science experiment. The convention is to use the independent variable as the x-axis and the dependent variable as the y-axis. The independent variables are the administration of the drug – the dosage and the timing. The dependent variable (sometimes known as the responding variable) is what is being studied and measured in the experiment. It’s what changes as a result of the changes to the independent variable.

What Is an Independent Variable? What Is a Dependent Variable?

Graphically, the slope is represented by three line types in elementary statistics. The independent and dependent variables may be viewed in terms of cause and effect. If the independent variable is changed, then an effect is seen in the dependent variable. Remember, the values of both variables may change in an experiment and are recorded.

Dependent and independent variables

Some non-experimental studies also have independent variables, but they may not be determined or manipulated by the investigators. The independent variable (sometimes known as the manipulated variable) is the variable whose change isn’t affected by any other variable in the experiment. There’s nothing you or anything else can do to speed up or slow down time or increase or decrease age.

The independent variable is the factor the researcher changes or controls in an experiment. It is called independent because it does not depend on any other variable. The independent variable may be called the “controlled variable” because it is the one that is changed or controlled.

Can you identify the independent and dependent variables for each of the four scenarios below? The answers are at the bottom of the guide for you to check your work. Build and test a range of simple and complex machines with this K’nex kit.

This doesn’t really make sense (unless you can’t sleep because you are worried you failed a test, but that would be a different experiment). This website is using a security service to protect itself from online attacks. There are several actions that could trigger this block including submitting a certain word or phrase, a SQL command or malformed data. A marketer changes the amount of money they spend on advertisements to see how it affects total sales. Our new student and parent forum, at, allow you to interact with your peers and the PrepScholar staff. See how other students and parents are navigating high school, college, and the college admissions process.

These terms are especially used in statistics, where you estimate the extent to which an independent variable change can explain or predict changes in the dependent variable. As the experimenter changes the independent variable, the effect on the dependent variable is observed and recorded. The two main variables in an experiment are the independent and dependent variable. If y is an
independent variable and you’re talking about the derivative with
respect to x, it would be 1/y. A researcher changes the version of a study guide given to students to see how it affects exam scores. Changing the plant growth rate affects the value of the amount of water.