Conducting a Science Fair Project
Your project should include controlled experimentation. In other words, if your experiment is done under carefully controlled conditions, what will happen? You, as the experimenter, will change certain conditions and observe how the condition of your subject is affected or changed. This experimentation provides a method for testing your hypotheses.
Your experimental design depends upon the experimentation that you are doing. Bacteria, mice or human beings will require different equipment and procedures than motors, soil and the weather. Whatever the experimentation or the subjects you use, there will probably be many variables. Two types of variables encountered in simple controlled experiments are:
1. INDEPENDENT VARIABLE
The experimenter changes something to observe what will happen. The "thing" changed is the independent variable.
2. DEPENDENT VARIABLE
These "things" that were changed caused something else to happen. The "something else" is the dependent variable.
For example, if the independent variable is the differing amounts of chemical fertilizer added to experimental groups of plants, then a dependent variable would be the difference in height between the experimental groups of plants.