La última actualización de esta entrada fue hecha el 20 abril, 2023 por Hernán R. Gómez
In a scientific experiment, whether in physics, chemistry, or another natural science discipline, it is very common to have to perform measurements and, with them, establish multiple operations that lead to various conclusions. In this way, it is important to recognize which factors produce or affect a phenomenon that we are studying.
What is a variable in science?
A variable is any aspect that can modify its value in an experiment.
Many phenomena studied during an experiment depend on various variables, which are necessary to obtain correct results in the laboratory. These are the important factors that we must take into account when experimenting and are defined as those data that can change in value during an experiment. It is necessary to pay attention to all possible variables that appear in an experiment.
Consequently, those variables that do not significantly affect the result or are of little importance should be eliminated (for example, we can cite the variable “age of the experimenter”: this variable is insignificant for studying the value of Earth’s gravity at a specific site, but it is significant for studying the incidence of an endemic disease in that site). When the time comes, each variable of the experiment should be modified to study the phenomenon.
In scientific research, variables are used to describe and measure the different factors that can influence the outcome of an experiment. There are three main types of variables: independent, dependent, and controlled. Each of these variables plays a unique role in the scientific process and helps researchers draw valid conclusions from their experiments. In this article, we will explore these three types of variables and provide examples of how they are used in scientific research.
Types of variables
There are three types of variables that we will detail below:
Independent Variables
Independent variables are the variables that the researcher manipulates or changes deliberately in an experiment. These variables are chosen by the researcher to test their hypothesis and see how they affect the dependent variable. For example, in an experiment testing the effects of caffeine on alertness, the independent variable is the amount of caffeine consumed by participants. The researcher can vary the amount of caffeine to see how it affects alertness, which is the dependent variable.
Another example of an independent variable is the age of participants in a study. Researchers may want to investigate how age affects cognitive function, so they deliberately select participants from different age groups and compare their performance on cognitive tasks. In this case, age is the independent variable.
Dependent Variables
Dependent variables are the variables that are measured or observed in an experiment. They are called “dependent” because their values depend on the independent variable. In our example of the effects of caffeine on alertness, alertness is the dependent variable. It is the variable that is affected by the amount of caffeine consumed by participants. The researcher measures alertness to determine the effect of caffeine on it.
Another example of a dependent variable is the amount of weight loss in a weight-loss program. Researchers may want to test the effectiveness of a particular diet or exercise program, so they measure the amount of weight lost by participants who follow the program. In this case, the amount of weight lost is the dependent variable.
Controlled Variables
Controlled variables are the variables that are kept constant in an experiment. They are used to ensure that any changes in the dependent variable are due to changes in the independent variable and not to other factors. For example, in an experiment testing the effects of caffeine on alertness, the temperature in the room could be a controlled variable. The researcher would keep the temperature constant throughout the experiment to ensure that it does not affect alertness.
Another example of a controlled variable is the type of measuring instrument used in an experiment. Researchers may want to investigate the effect of a particular treatment on blood pressure, so they use the same type of blood pressure cuff to measure blood pressure for all participants. This ensures that any changes in blood pressure are due to the treatment and not to differences in the measuring instrument.
Conclusion
In conclusion, independent, dependent, and controlled variables are important components of scientific research. Independent variables are the variables that are manipulated or changed deliberately in an experiment. Dependent variables are the variables that are measured or observed in an experiment and are affected by the independent variable. Controlled variables are the variables that are kept constant in an experiment to ensure that changes in the dependent variable are due to changes in the independent variable. Understanding these types of variables is essential for conducting valid and reliable scientific research.
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