Controlled Variable Definition for Kids

Controlled Variable Definition for Kids


In an experiment, there are elements that are beyond your control. These could be constants or variables. Then there are elements that can be controlled. Such elements are changed or kept constant depending on the demands of the experiment, including the aim or objective. There are some fixed elements which are constants and some elements that change or can be changed which are called variables. The elements whose values can be changed can be classified into three types: dependent variable, independent variable and controlled variable.

Controlled Variable: Explained!

In simple words, a controlled variable is any element, quantum or feature in a given experiment or equation that can be fixed or would not be changed at all during the course of the experiment or equation. The controlled variable is not a constant. The element, its value or quantum can be changed but it would not be changed. Now, let us understand the dependent and independent variables to have a more lucid explanation of a controlled variable.

In any scientific experiment or even an equation, there will be many elements. Some elements are constant and some are variables. You cannot have all variables fluctuating or changing their values through the equation or the course of the experiment. Then, you would not have the desired result or outcome. The aim of the experiment will remain unaccomplished.

Usually, there is a cause of a reaction or process, an element that reacts and another element that facilitates the reaction. This is a simple way of explaining a scientific experiment, physical or mathematical equation and even chemical processes. The experimenter has to fix an element so it facilitates the equation or experiment in a specific way and doesn’t behave randomly or have any effects that are untraceable or unnecessary. This is the controlled variable. The experimenter needs one variable to have fluctuating values which is essentially the causal element. This is the independent variable. The value of this element can be changed at will. The independent variable and the controlled variable would facilitate the outcome which is the dependent variable. It must be noted that the dependent variable is not a constant. The value will change depending on the chosen value of the controlled variable and the specific value of the independent variable in a given equation or an experiment.

The value of a controlled variable will remain the same in one specific experiment regardless of how many times the same experiment is repeated with different values of the independent variable. The outcome which is the dependent variable will change depending on the value of the independent variable while acknowledging the constant value of the controlled variable.

Significance & Illustration of Controlled Variable

A controlled variable is quintessential in an experiment that has more than two elements, where the two elements are one cause and one outcome. If there are two elements in the causal phase, then one has to be controlled. If both elements change their values then the change in the outcome cannot be attributed to either of the elements or both. It would be difficult to truly understand which element changed the outcome and to what extent when their corresponding values underwent a change. Hence, one element must be fixed. The value must be unchanged. Changing the value of the other element, which is the independent variable, will lead to a change in the value of the outcome, the dependent variable.

Controlled variable is more than significant. It is quintessential for any experiment that has more than two elements. In cases where there are multiple elements, say four or more, there can be more than one controlled variable. It is quite desirable to have just one independent variable and all other controlled variables leading to one dependent variable. That is the simplest and fairest of all scientific experimentations or mathematical equations.

A controlled variable has to be an element that can be managed or kept constant. If the value is beyond the control of the experimenter then it cannot be a controlled variable. However, most elements can be controlled, be it the amount of light, temperature, force, humidity or time. It may be argued that time cannot be stopped or sped up so one doesn’t actually get to control time. But you can always fix the time. It is possible that a certain chemical process takes two minutes and another takes three minutes. By opting for a fixed time for both experiments, say two and a half minutes, you can observe the changes of the elements in regards to the allotted time.

Over the years, it has been formulated and also made imperative that only one independent variable be used in an experiment to have one outcome, the dependent variable. All other elements must be controlled variables. You can change that by controlling the independent variable and allowing one controlled variable to become independent in another set of experiments.