After three months, we measure the stress levels of each person and compare the groups. In these experimental studies, the independent variable was graphic video games, and the dependent variable was observed level of aggression. Sometimes you may hear this variable called the "controlled variable" because it is the one that is changed. Dependent and Independent variables Example of Denominator In p = 4q, p is the dependent variable, because its value depends on the value of q. The independent variable in your experiment would be the brand of paper towel. An independent variable is the variable you manipulate, control, or vary in an experimental study to explore its effects. In statistics, dependent variables are also called: Response variables (they respond to a change in another variable) Their muscle mass is measured, and only those with a lower level are selected for the study, leaving a total of 80 study participants. the mud) the outcome variable. BSc (Hons) Psychology, MRes, PhD, University of Manchester. Although there are a lot of obvious limitations to this hypothetical, it is the first step. 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. Each shopper is given a box of the same food and drink items and sent to one of the rooms. A company that specializes in essential oils wants to examine the effects of lavender on sleep quality. At the end of three months, all the students take the same test that assesses critical thinking skills. The dependent variable is the condition that you measure in an experiment. The dependent variable is the volume of liquid absorbed by the paper towel. The different levels of the independent variable are called conditions. Independent Variable in Psychology: Examples and Importance - Verywell Mind Disclaimer. Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Olivia Guy-Evans is a writer and associate editor for Simply Psychology. If, say, y = x+3, then the value y can have depends on what the value of x is. Type of light the tomato plant is grown under, Presence or absence of intermittent fasting, Presence or absence of medical marijuana use, Type of work environment (remote or in office). Experiments have two fundamental features. Each version contains a different blend of specially developed chemicals. You can also apply multiple levels to find out how the independent variable affects the dependent variable. https://doi.org/10.1080/08854726.2014.959374, https://doi.org/10.1080/10790195.2012.10850354. What is the difference between discrete and continuous variables? People learn more when they study in a quiet versus noisy place. Is the variable manipulated, controlled, or used as a subject grouping method by the researcher? For example, in a plant growth study, the independent variables might be soil moisture (continuous) and type of fertilizer (categorical). (2012). Bevans, R. A confounding variable in the example of car exhaust and asthma would be differential exposure to other factors that increase respiratory issues, like cigarette smoke or particulates from factories. Time of day has a significant effect on alertness. She has taught science courses at the high school, college, and graduate levels. One of the most popular forms of regression analysis is linear regression, which allows you to establish a linear relationship between a dependent variable and one or more independent variables. February 3, 2022 For example, in an experiment looking at the effects of studying on test scores, studying would be the independent variable. 2015;21(1):39-49. doi: 10.1080/08854726.2014.989799. . Tutors' Association ID: 55870609, Join Grad Coach On: Facebook | Twitter | YouTube | LinkedIn, Qualitative Data Analysis Methods 101: The Big 6 Methods (Including Examples), How To Write A Dissertation Or Thesis 101: Big Picture Guide (With Examples). Retrieved March 3, 2023, Learn more about our academic and editorial standards. Afterward, their level of aggression was measured via a wide range of methods, including direct observations of their behavior, their actions when given the opportunity to be aggressive, or a variety of other measures. Independent vs. Dependent Variables | Definition & Examples - Scribbr For example, scientists can learn if graphic video games make people more aggressive, if mediation reduces stress, if Gatorade improves athletic performance, and even if certain medical treatments can cure cancer. Below are the key differences when looking at an independent variable vs. dependent variable. For example, if you're studying whether a change in temperature affects productivity, the independent variable would be the room temperature, and the dependent . National Library of Medicine . If you want to test whether some plant species are more salt-tolerant than others, some key variables you might measure include the amount of salt you add to the water, the species of plants being studied, and variables related to plant health like growth and wilting. These alternative explanations are closely related to the concept of internal validity. By varying the level of the independent variable and observing associated changes in the dependent variable, a researcher can conclude whether the independent variable affects the dependent variable or not. For example, in Darley . This can provide very valuable information when studying just about any subject. You want to determine whether a chemical is essential for rat nutrition, so you design an experiment. Here are the definitions for independent and dependent variables, examples of each variable, and the explanation for how to graph them. Each athlete will run on a treadmill for one hour while their heart rate is tracked. independent and dependent variable examples thoughtco, understanding co2 lasers, inferring from data home ubalt edu, independent variables and dependent . Read our, Introduction to Psychology Research Methods, Internal Validity vs. Bhandari, P. She has previously worked in healthcare and educational sectors. The independent variable is the variable that is being manipulated, or the one that varies. If you determine the substance is necessary for proper nutrition, a follow-up experiment might determine how much of the chemical is needed. His work has involved designing teacher certification for Trinity College in London and in-service training for state governments in the United States. Kendra Cherry, MS, is an author and educational consultant focused on helping students learn about psychology. Unable to load your collection due to an error, Unable to load your delegates due to an error. 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. Please include what you were doing when this page came up and the Cloudflare Ray ID found at the bottom of this page. Helmenstine, Anne Marie, Ph.D. (2020, August 27). Federal government websites often end in .gov or .mil. In an experiment to determine how far people can see into the infrared part of the spectrum, the wavelength of light is the independent variable and whether the light is observed is the dependent variable. 5.1 Experiment Basics - Research Methods in Psychology What part of the experiment does the variable represent? People who exercise regularly sleep better at night. You plot bars for each treatment group before and after the treatment to show the difference in blood pressure. Independent Variable Definition and Examples - ThoughtCo.com is the Here are the definitions for independent and dependent variables, examples of each variable, and the explanation for how to graph them. At the end of three months, the muscle mass of all participants is measured. Independent, Dependent, and Other Variables in Healthcare and Clarify mathematic question In mathematics, an equation is a statement that two things are equal. We could measure blood pressure, or the amount of the stress hormone cortisol in their blood, or by using a paper and pencil measure such as a questionnaire that asks them how much stress they feel. Example one: How long you use your phone before bed affects your quality of sleep. It is sometimes called the 'predictor' or 'treatment' variable. If you want to know whether caffeine affects your appetite, the presence/absence or amount of caffeine is the independent variable. A business wants to determine if giving employees more control over how to do their work leads to increased job satisfaction. The health of the plants (height, amount and size of flowers and fruit, color) is the dependent variable. It would also be possible to examine the physical effects of car exhaust on the brain by conducting an autopsy. Its not possible to randomly assign these to participants, since these are characteristics of already existing groups. Definition and examples of dependent variable Independent variables are the ones we can freely manipulate, by plugging in any input value. So, they use Photoshop to manipulate the same image of a female by altering the color of her hair: blonde, brunette, red, and brown. The independent variable in this sleep study is lavender, and the dependent variable is the total amount of time spent in deep sleep. Other types of variables have interchangeable terms. In a study to determine whether how long a student sleeps affects test scores, the independent variable is the length of time spent sleeping while the dependent variable is the test score. Click to reveal The independent variable is one that the researchers either manipulate (such as the amount of something) or that already exists but is not dependent upon other variables (such as the age of the participants). They already have a pool of consumers that fit their customer profile and they often use them for testing. Educators, social scientists, and parents were shocked at how graphic games were becoming. Journal of Health Care Chaplaincy, 20(4), 161170. Then, you select an appropriate statistical test to test your hypothesis. For example, economists may want to find out what . In this particular example, the type of information is the independent variable (because it changes), and the amount of information remembered is the dependent variable (because this is being measured). Next, they randomly select university males to enter their testing facilities. Independent and Dependent Variables Examples - Science Notes and Projects This includes rankings (e.g. What is an example of an independent and a dependent variable? Another way to put it is the dependent variable is the output value and the independent variable is the input value. This article was peer-reviewed and edited by Chris Drew (PhD). 2008;14(1):3-19. doi: 10.1080/08854720802053796. The direction of a correlation can be either positive or negative. They hire a sleep research lab to conduct the study. 1 Solve word questions too You want to know which brand of fertilizer is best for your plants. The independent variable (IV) in psychology is the characteristic of an experiment that is manipulated or changed by researchers, not by other variables in the experiment.