Conducting a science experiment is a lot of fun, but it can be a bit confusing at first. One of the key elements of a successful experiment is understanding the variables involved. Variables are the elements that can be changed, tested, and measured within an experiment. Typically, there are three types of variables used in a science experiment: independent, dependent, and controlled.
Independent Variable
The independent variable is the one that is changed or manipulated by the person conducting the experiment. In other words, the experimenter is in control of this particular variable. This type of variable is used to test the effect it has on the dependent variable. For example, if testing the effect of sunlight on the growth of a plant, then the amount of sunlight is the independent variable.
Dependent Variable
The dependent variable is the one that is affected by the independent variable. In the previous example, the dependent variable is the growth of the plant. The experimenter does not have control over this variable, as it is determined by the independent variable. The experimenter is simply measuring the dependent variable to observe the effect that the independent variable has on it.
Controlled Variables
Controlled variables are those that are kept constant during an experiment. For example, if testing the effect of temperature on the growth of a plant, then the amount of water, sunlight, and soil must remain the same. If not, then it is impossible to truly determine the effect that temperature has on the growth of the plant.
How to Control Variables
Controlling variables is a key part of conducting a successful experiment. One way of controlling variables is to use a control group. This is the group that does not receive the treatment that the experimental group does. This allows the experimenter to compare the experimental group to the control group and see the effect of the independent variable. Another way of controlling variables is to use blind experiments. In this type of experiment, the experimenter does not know which group is the experimental group and which is the control group. This eliminates the possibility of bias on the part of the experimenter.
Types of Experiments
There are two main types of experiments used in science: observational and experimental. Observational experiments involve observing and recording data without manipulating the variables. They are used to gain an understanding of the natural world and how it works. Experimental experiments involve manipulating one or more variables to observe the effects on the dependent variable. This type of experiment is used to test specific hypotheses and draw conclusions.
How to Design an Experiment
Designing a successful experiment requires careful planning and consideration. The first step is to form a hypothesis. This is a statement that predicts the outcome of an experiment. The next step is to identify the independent and dependent variables, as well as any controlled variables. Once this is done, the experimenter can create a procedure to test the hypothesis and measure the results. Finally, the results must be analyzed and compared to the hypothesis to determine whether it is supported or not.
Conclusion
Understanding the different types of variables used in science experiments is essential for conducting a successful experiment. Independent variables are those that are changed or manipulated by the experimenter, while dependent variables are those that are affected by the independent variable. Controlled variables are those that are kept constant during an experiment. Finally, experiments can either be observational or experimental, and require careful planning and consideration.