What is the difference between a variable and a constant and why is the difference important for testing hypotheses?
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The scientific method forms the foundation of the collective knowledge of the world around us. It is how researchers figure out what is likely true in nature. A scientific method experiment begins with a hypothesis, which is an informed opinion that explains why certain things occur the way they do. In science, hypotheses lead to predictions. These are measurable events that occur during an experiment if the hypothesis is true. The most significant components of the scientific method include hypotheses, dependent and independent variables, constant variables and control groups. Show
TL;DR (Too Long; Didn't Read)A constant variable is an aspect of an experiment that a scientist or researcher keeps unchanged. There can be more than one constant in an experiment. Through rigorous experimentation and corroboration, which requires other scientists to duplicate the same result as the first, a scientist's hypothesis is either confirmed or proven incorrect. While many people think of only men and women in white lab coats using the scientific method, it is an intuitive process. If you've ever asked yourself whether something is true or why something is the way it is—why is the sky blue?—you've performed the first step of the scientific method. Why the Scientific Method Is ImportantThere is a good reason teachers introduce the scientific method early in a science class. It's the most important fundamental tool of science. Without the scientific method, there would be no way for scientists to agree on what is likely true and what is not. The term "science" comes from the Latin word for "knowing." The scientific method is the process used to know that a new idea is valid. The confirmation of these new ideas has both theoretical and practical implications. For example, they can increase our knowledge of the universe and how it works. New ideas can lead to the development of inventions that change how people live. There are three types of variables used in scientific experiments: constant, independent and dependent. What Is a Constant in the Scientific Method?A constant variable is any aspect of an experiment that a researcher intentionally keeps unchanged throughout an experiment. Experiments are always testing for measurable change, which is the dependent variable. You can also think of a dependent variable as the result obtained from an experiment. It is dependent on the change that occurs. Scientists introduce an independent variable to an experiment to create a change in the dependent variable. There can only be one independent variable in each experiment, but there will normally be many constant variables. To illustrate a constant variable by looking at an example, let's say a new drug comes out that claims to make it easier to lose weight. Each scientific experiment can only focus on one independent variable or make one change at a time. If researchers gave a group of people this new drug and also increased the amount of exercise each person in the study did, it would complicate the picture. Scientists wouldn't be able to tell whether the pill or the exercise was responsible for any changes in weight, the dependent variable. To ensure that only one independent variable exists, everything else is held constant. So, the constant variables in this experiment investigating the effects of the diet pill would be variables like the number of calories consumed by each participant, the amount of exercise they get, how much sleep they receive, etc. The constants are all the other aspects that are held the same for each participant. Difference Between a Control and a ConstantYou may think that a constant is the same thing as a control, but there is a difference. A control is specifically set aside without any changes to give the researcher an objective picture of any changes in the independent variable. For studies of drugs, a placebo is the control. A person is not told whether they're taking a diet pill or a placebo. A control negates the possible effects of persons believing they are taking diet pills when they are not. When using the experimental method, it is critical to understand which variables are constants and which are controls. This helps to ensure any changes to the dependent variable are a result of the independent variable alone. Related ArticlesHow to Eliminate Bias in Qualitative ResearchWhy Should You Only Test for One Variable at a Time...10 Characteristics of a Science ExperimentThe Definition of an Uncontrolled VariableWhat Is the Difference Between a Control & a Controlled...What Is the Meaning of Variables in Research?Can a Science Experiment Have Two Manipulated Variables?Difference Between Proposition & HypothesisSteps & Procedures for Conducting Scientific ResearchWhat Are Constants & Controls of a Science Project...Five Characteristics of the Scientific MethodHow to Do a Science Fair Project LogbookWhat Is a Positive Control in Microbiology?What Are Comparative Experiments?What Is a Standardized Variable in Biology?Distinguishing Between Descriptive & Causal StudiesDifferences Between Conceptual Independent Variables...Research Methods in ScienceHow to Calculate SignificanceReferences
About the Author Amanda Cook holds a Bachelor of Science in Microbiology and a Doctorate in Health and Human Performance from Middle Tennessee State University. She has been writing online professionally since 2009. What is the difference between a variable and a constant in research?What is the Difference between Constant and Variables? A constant does not change its value over time. A variable, on the other hand, changes its value dependent on the equation. Constants are usually written in numbers.
Why are control variables important in testing hypotheses?Control variables enhance the internal validity of a study by limiting the influence of confounding and other extraneous variables. This helps you establish a correlational or causal relationship between your variables of interest and helps avoid research bias.
Why is it important to have constants and only test one variable at a time?Testing only one variable at a time lets you analyze the results of your experiment to see how much a single change affected the result. If you're testing two variables at a time, you won't be able to tell which variable was responsible for the result.
What is constant in hypothesis?Science experiments also include something called constants. A constant is the part that doesn't change during the experiment.
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