1. Independent Variable:
* This is the factor that the experimenter manipulates or changes.
* It's the "cause" in a cause-and-effect relationship.
* Example: In an experiment testing the effect of fertilizer on plant growth, the independent variable is the amount of fertilizer.
2. Dependent Variable:
* This is the factor that is measured or observed in response to changes in the independent variable.
* It's the "effect" in a cause-and-effect relationship.
* Example: In the same experiment, the dependent variable is the plant height measured after a certain period.
3. Controlled Variables:
* These are factors that are kept constant throughout the experiment to ensure that only the independent variable is affecting the dependent variable.
* They help to isolate the effect of the independent variable.
* Example: In the plant growth experiment, controlled variables could include the type of plant, the amount of sunlight, the temperature, and the amount of water.
In summary:
* The independent variable is what you change.
* The dependent variable is what you measure.
* Controlled variables are kept constant to avoid influencing the results.
By manipulating the independent variable and measuring the dependent variable while keeping all other variables constant, you can determine the effect of the independent variable on the dependent variable. This is the fundamental principle of scientific experimentation.
