1. Independent Variable (IV): This is the variable that the researcher manipulates or changes in an experiment. The IV is the cause in a cause-and-effect relationship. For example:
* Experiment: Studying the effect of fertilizer on plant growth.
* IV: The amount of fertilizer applied.
2. Dependent Variable (DV): This is the variable that is measured or observed in an experiment. It is the effect in a cause-and-effect relationship. It is *dependent* on the independent variable. For example:
* Experiment: Studying the effect of fertilizer on plant growth.
* DV: The height of the plant.
3. Controlled Variable (CV): These are variables that are kept constant throughout the experiment to ensure that only the independent variable is affecting the dependent variable. They help eliminate extraneous factors that could influence the results. For example:
* Experiment: Studying the effect of fertilizer on plant growth.
* CV: The type of plant, amount of sunlight, and amount of water each plant receives.
It's important to remember that these are just the most common types of variables. There are other types, like confounding variables (uncontrolled variables that could affect the results) and moderator variables (variables that can influence the relationship between the IV and DV).
