examples of independent and dependent variables in healthcare
An official website of the United States government. 2022 Aug;27(5):436-446. doi: 10.1177/17449871211051566. Information biasrefers to a systematic error due to inaccurate measurement or classification of disease, exposure, or other variables.[3] Recall bias, a type of information bias, occurs when study participants do not remember the information they report accurately or completely. Nominal and categorical variables describe samples in groups based on counts that fall within each category, have no quantitative relationships, and cannot be ranked. Half are given Gatorade, and the other half are given water, but no one knows what they are given because both liquids have been colored. Is this variable measured as an outcome of the study? Dr. Cornell has worked in education for more than 20 years. In z = 3x2 - 2y3, z is the dependent variable. Are researchers trying to identify how the variable influences another variable? A dependent variable is a variable whose value depends upon independent variable s. The dependent variable is what is being measured in an experiment or. When you collect quantitative data, the numbers you record represent real amounts that can be added, subtracted, divided, etc. In this highly unrealistic study, the independent variable is vitamins, and the dependent variable is health, as measured by blood pressure and cholesterol levels. These concepts should not be confused with predictor and outcome variables. Quantitative Data Analysis 101: Methods, Techniques & Terminology Explained. How do we define young, old, or memory? Of course, you could also measure the number of unpopped kernels instead. 2. To keep track of your salt-tolerance experiment, you make a data sheet where you record information about the variables in the experiment, like salt addition and plant health. It is sometimes called the 'predictor' or 'treatment' variable. After many claims that listening to Mozart will make you smarter, a group of education specialists decides to put it to the test. Appetite is the dependent variable. A dependent variable is the variable that changes as a result of the independent variable manipulation. An independent variable is the variable you manipulate, control, or vary in an experimental study to explore its effects. An operational definition describes exactly what the independent variable is and how it is measured. The dependent variable is the biomass of the crops at harvest time. The brand of popcorn is the independent variable. Statistical models will estimate effect sizes for the independent variables. Independent and Dependent Variable Examples, How to Tell the Independent and Dependent Variable Apart. ____________________________________________________________, I.V. For example, in Darley . Brain morphology, harm avoidance, and the severity of excessive internet use. The article explains that the terms extraneous, nuisance, and confounding variables refer to any variable that can interfere with the ability to establish relationships between independent variables and dependent variables, and it describes ways to control for such confounds. Determining cause and effect is one of the most important parts of scientific research. official website and that any information you provide is encrypted Sometimes you may hear this variable called the "controlled variable" because it is the one that is changed. Instead, you can create a research design where you compare the outcomes of groups of participants with characteristics. variable, or in the form (x2 + y2 ) dx dy 2xy = 0, where x is the dependent variable and y is the independent variable. It is the variable you control. sharing sensitive information, make sure youre on a federal They already have a pool of consumers that fit their customer profile and they often use them for testing. Quantitative variables are any variables where the data represent amounts (e.g. To ensure cause and effect are established, it is important that we identify exactly how the independent and dependent variables will be measured; this is known as operationalizing the variables. The temperature and light in the room the plants are kept in, and the volume of water given to each plant. Do tomatoes grow fastest under fluorescent, incandescent, or natural light? Published on 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). 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. Discrete and continuous variables are two types of quantitative variables: If you want to cite this source, you can copy and paste the citation or click the Cite this Scribbr article button to automatically add the citation to our free Citation Generator. https://helpfulprofessor.com/independent-and-dependent-variable-examples/. A randomized, controlled trial of meditation for work stress, anxiety and depressed mood in full-time workers. The subject of confounding and bias relates to a larger discussion of the relationship between correlation and causation. Here are some examples of research questions and corresponding independent and dependent variables. Each version contains a different blend of specially developed chemicals. 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). The independent variable in this sleep study is lavender, and the dependent variable is the total amount of time spent in deep sleep. Olivia Guy-Evans is a writer and associate editor for Simply Psychology. PMC Of course, they would prefer that consumers enter and exit quickly to increase sales volume and profit. Pot size and soil type might affect plant survival as much or more than salt additions. In another example, the hypothesis Young participants will have significantly better memories than older participants is not operationalized. For example, if we want to explore whether high concentrations of vehicle exhaust impact incidence of asthma in children, vehicle exhaust is the independent variable while asthma is the dependent variable. Here, the amount of chemical is the independent variable and the rat health is the dependent variable. Participants aged between 16 30 will recall significantly more nouns from a list of twenty than participants aged between 55 70 is operationalized. In other cases, researchers might find that changes in the independent variables have no effect on the variables that are being measured. 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). You can email the site owner to let them know you were blocked. 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 a plant growth study, the independent variables might be soil moisture (continuous) and type of fertilizer (categorical). About The Helpful Professor This website is using a security service to protect itself from online attacks. This makes sense, but: Example: Your test score affects how long you sleep. The independent variable is the teaching method, and the dependent variable is performance on the critical thinking test. Social class has a significant effect on IQ scores. The type of visualization you use depends on the variable types in your research questions: To inspect your data, you place your independent variable of treatment level on the x-axis and the dependent variable of blood pressure on the y-axis. The only way to do that is to manipulate the independent variable and observe any changes in the dependent variable. The presence/absence of the chemical is the independent variable. Each shopper is given a box of the same food and drink items and sent to one of the rooms. So for y=x+3, when you input x=2, the output is y = 5. Non-manipulation quantitative designs. Groups that are ranked in a specific order. As an example, if we state that higher intelligence causes improved learning among students, then intelligence is an independent variable and learning is a dependent variable. Below are the key differences when looking at an independent variable vs. dependent variable. Independent and Dependent Variable Examples The presence/absence of the chemical is the independent variable. You need to know which types of variables you are working with in order to choose appropriate statistical tests and interpret the results of your study. Although there are many types of bias, two common types are selection bias and information bias. To what extent does remote working increase job satisfaction? This is because individuals that had a particularly bad (or good) experience with the physician may be more likely to go to the website and provide a rating. An example of a dependent variable is how tall you are at different ages. To determine the effect that traffic patterns have on the air in a city, employees at the agency perform a study that assesses car usage and air quality in cities around the country. A group of health scientists decides to conduct a study to determine if taking vitamins improves health. Your email address will not be published. If you want to cite this source, you can copy and paste the citation or click the Cite this Scribbr article button to automatically add the citation to our free Citation Generator. If we didnt do this, then it would be very difficult (if not impossible) to compare the findings of different studies to the same behavior. December 2, 2022. In quantitative research, its good practice to use charts or graphs to visualize the results of studies. The health of the rat (whether it lives and can reproduce) is the dependent The independent variable in your experiment would be the brand of paper towel. One is called the dependent variable, and the other is the independent variable. Retrieved from https://www.thoughtco.com/independent-and-dependent-variable-examples-606828. Definition and Design, The Differences Between Explanatory and Response Variables, The Role of a Controlled Variable in an Experiment, Ph.D., Biomedical Sciences, University of Tennessee at Knoxville, B.A., Physics and Mathematics, Hastings College. Bethesda, MD 20894, Web Policies Changes in . Can graphic video games be a force for good? To gather information about plant responses over time, you can fill out the same data sheet every few days until the end of the experiment. For example, allocating participants to drug or placebo conditions (independent variable) to measure any changes in the intensity of their anxiety (dependent variable). (2012). 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. Dependent variable Definition and Examples. It's the outcome you're interested in measuring, and it 'depends' on your independent variable. If you have ever wondered if this is true or not, then you are in luck because there is a way to know one way or the other. Weiten, W. Psychology: Themes and Variations, 10th ed. You randomly assign your patients to one of the three groups: A true experiment requires you to randomly assign different levels of an independent variable to your participants. When you do correlational research, the terms dependent and independent dont apply, because you are not trying to establish a cause and effect relationship (causation). Our website is not intended to be a substitute for professional medical advice, diagnosis, or treatment. The presence/absence of the chemical is the independent variable. By manipulating the level of an independent variable and observing corresponding changes in a dependent variable, scientists can gain an understanding of many phenomena. Independent variable causes an effect on the dependent variable. Each participant sits in front of a computer screen and responds to questions on a survey. During the first three months of the academic year, they randomly select some 5th-grade classrooms to listen to Mozart during their lessons and exams. I.V._____________________________________________________________, D.V. A dependent variable is the variable that changes as a result of the independent variable manipulation. The research would look something like this: laboratory rats would be raised in three different rooms that varied in the degree of car exhaust circulating in the room: no exhaust, little exhaust, or a lot of exhaust. You manipulate the independent variable (the one you think might be the cause) and then measure the dependent variable (the one you think might be the effect) to find out what this effect might be. Stressful experiences significantly increase the likelihood of headaches. How should we measure stress? In these cases you may call the preceding variable (i.e., the rainfall) the predictor variable and the following variable (i.e. A variable that is made by combining multiple variables in an experiment. 2023 Dotdash Media, Inc. All rights reserved. Distinguishing between independent and dependent variables can be tricky when designing a complex study or reading an academic research paper. (2022, December 02). 1. September 19, 2022 Are you ready to take control of your mental health and relationship well-being? The company wants to claim that when an athlete drinks Gatorade, their performance will improve. Epub 2021 Oct 25. Amanda Tust is a fact-checker, researcher, and writer with a Master of Science in Journalism from Northwestern University's Medill School of Journalism. You need to know what type of variables you are working with to choose the right statistical test for your data and interpret your results. The brand of fertilizer is the independent variable. The independent variable is the level of crust crunchiness, and the dependent variable is how much it was liked. In statistics, dependent variables are also called: Response variables (they respond to a change in another variable) You want to know which brand of microwave popcorn pops the best. A group of teachers is interested in which teaching method will work best for developing critical thinking skills. Independent and Dependent Variables: Differences & Examples The independent variable is the variable the experimenter manipulates or changes, and is assumed to have a direct effect on the dependent variable. Dave Cornell (PhD) and Peer Reviewed by Chris Drew (PhD), Definition of Independent and Dependent Variables, Examples of Independent and Dependent Variables, 1. In this study, despite the ethical issues (remember this is just a hypothetical example), the independent variable is chemotherapy, and the dependent variable is tumor size. His work has involved designing teacher certification for Trinity College in London and in-service training for state governments in the United States. An ordinal variable can also be used as a quantitative variable if the scale is numeric and doesnt need to be kept as discrete integers. 8600 Rockville Pike 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 (the response) is the dependent variable. You plot bars for each treatment group before and after the treatment to show the difference in blood pressure. Their R&D food scientists have developed a protein supplement that is designed to help build muscle mass for people that work out regularly. Careers. Because the researcher controls the level of the independent variable, it can be determined if the independent variable has a causal effect on the dependent variable. What Are Independent and Dependent Variables? Published on Because it would be unethical to expose a randomized group of people to high levels of vehicle exhaust,[1] a study comparing two populations with differential exposure to vehicle exhaust would rely on a natural experiment, or a situation in which this already occurs due to factors unrelated to the researchers. Kaliyadan F, Kulkarni V. Types of variables, descriptive statistics, and sample size. By Kendra Cherry J Exp Soc Psychol. Women are more attracted to men without earrings than men with earrings. Operational variables (or operationalizing definitions) refer to how you will define and measure a specific variable as it is used in your study. If you are designing an experiment, here are a few tips for choosing an independent variable (or variables): It is also important to be aware that there may be other variables that might influence the results of an experiment. To understand this concept, it's helpful to take a look at the independent variable in research examples. The dependent variable would be the amount of liquid absorbed by the paper towel. The independent variable is the supplement, and the dependent variable is muscle mass. Before The independent variable and dependent variable are used in a very specific type of scientific study called the experiment. In an experiment, one group of students attends an after-school tutoring session twice a week while another group of students does not receive this additional assistance. So, they rent space in a large shopping mall and create three different simulated restaurant interiors of different colors. https://doi.org/10.1080/08854726.2014.959374, https://doi.org/10.1080/10790195.2012.10850354. Helmenstine, Anne Marie, Ph.D. "What Are Independent and Dependent Variables?" What is the effect of intermittent fasting on blood sugar levels? Your IP: You want to compare brands of paper towels, to see which holds the most liquid. A well-known fast-food corporation wants to know if the color of the interior of their restaurants will affect how fast people eat. It is the main point of focus in the experiment whereby researchers are looking to find a cause to. Two other kinds of variables that might influence the outcome include: Extraneous variables can also include demand characteristics (which are clues about how the participants should respond) and experimenter effects (which is when the researchers accidentally provide clues about how a participant will respond). A confounding variable is related to both the supposed cause and the supposed effect of the study. The independent variable is Mozart, and the dependent variable is exam scores. In this case, we must state what we mean by the terms media violence and aggression as we will study them. confounds; dependent variable; independent variable; levels of measurement; mediation; moderation; risk factors. [8] Examples of these variables include: Blazing Angels or Resident Evil? They then indicate how much they liked it by pressing one of 5 buttons: didnt like at all, liked, somewhat liked, liked very much, loved it. Does this variable get measured only after other variables are altered? Of course, there are a lot of issues to consider when conducting an experiment, but these are the basic principles. Unauthorized use of these marks is strictly prohibited. In your research design, its important to identify potential confounding variables and plan how you will reduce their impact. The experiment is an incredibly valuable way to answer scientific questions regarding the cause and effect of certain variables. However, there might be cases where one variable clearly precedes the other (for example, rainfall leads to mud, rather than the other way around). There are three types of categorical variables: binary, nominal, and ordinal variables. 2022 Jul;43(10):3176-3183. doi: 10.1002/hbm.25842. There can be all different types of independent variables. It further explains that even though intervening, mediating, and moderating variables explicitly alter the relationship between independent variables and dependent variables, they help to explain the causal relationship between them. The health of the plants (height, amount and size of flowers and fruit, color) is the dependent variable. This article begins by defining the term variable and the terms independent variable and dependent variable, providing examples of each. The dependent variable is the response that is measured. The independent variable was the airbag and the dependent variable was the amount of skull damage. from https://www.scribbr.com/methodology/types-of-variables/, Types of Variables in Research & Statistics | Examples, , the terms dependent and independent dont apply, because you are not trying to establish a cause and effect relationship (. Verywell Mind's content is for informational and educational purposes only. An example of a dependent variable is depression symptoms, which depends on the independent variable (type of therapy). ANOVA tells you if the dependent variable changes according to the level of the independent variable. Kendra Cherry, MS, is an author and educational consultant focused on helping students learn about psychology. For the following hypotheses, name the IV and the DV and operationalize both variables. After a certain period of time, perhaps several months, the effects on cognitive performance could be measured.
