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This graph show speed as a function of time. Urocyon / Wikimedia Commons / Public Fomain Updated on March 01, 2022 The two main variables in an experiment are the independent and dependent variable. An independent variable is the variable that is changed or controlled in a scientific experiment to test the effects on the dependent variable. A dependent variable is the variable being tested and measured in a scientific experiment. The dependent variable is 'dependent' on the independent variable. As the experimenter changes the independent variable, the effect on the dependent variable is observed and recorded. Independent vs Dependent Variable
Independent and Dependent Variable ExamplesFor example, a scientist wants to see if the brightness of light has any effect on a moth being attracted to the light. The brightness of the light is controlled by the scientist. This would be the independent variable. How the moth reacts to the different light levels (distance to light source) would be the dependent variable. As another example, say you want to know whether or not eating breakfast affects student test scores. The factor under the experimenter's control is the presence or absence of breakfast, so you know it is the independent variable. The experiment measures test scores of students who ate breakfast versus those who did not. Theoretically, the test results depend on breakfast, so the test results are the dependent variable. Note that test scores are the dependent variable, even if it turns out there is no relationship between scores and breakfast. For another experiment, a scientist wants to determine whether one drug is more effective than another at controlling high blood pressure. The independent variable is the drug, while patient blood pressure is the dependent variable. In some ways, this experiment resembles the one with breakfast and test scores. However, when comparing two different treatments, such as drug A and drug B, it's usual to add another variable, called the control variable. 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. How to Tell the Variables ApartThe 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. The difference is that the value of the independent variable is controlled by the experimenter, while the value of the dependent variable only changes in response to the independent variable. Remembering Variables With DRYMIXWhen results are plotted in graphs, the convention is to use the independent variable as the x-axis and the dependent variable as the y-axis. The DRY MIX acronym can help keep the variables straight: D is the dependent variable M is the manipulated variable or the one that is changed in an experiment Independent vs Dependent Variable Key Takeaways
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What is the relationship between the dependent and independent variables called?In a research experiment, the dependent variables are usually the effect, while the independent variables are the cause. Also, the relationship between the dependent and independent variables can be said to be a cause and effect relationship.
What is the relationship between independent and dependent variables give one example?For example, if you are measuring how the amount of sunlight affects the growth of a type of plant, the independent variable is the amount of sunlight. You can control how much sunlight each plant gets. The growth is the dependent variable. It is the effect of the amount of sunlight.
How would you describe the relationship between independent and dependent variables in each graph?The independent variable belongs on the x-axis (horizontal line) of the graph and the dependent variable belongs on the y-axis (vertical line). The x and y axes cross at a point referred to as the origin, where the coordinates are (0,0).
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