1. Independent Variable:
* This is the variable that the experimenter *manipulates* or changes.
* It is the "cause" in a cause-and-effect relationship.
* The independent variable is what you are testing.
* Example: In an experiment testing the effect of fertilizer on plant growth, the independent variable is the *amount of fertilizer* given to each plant.
2. Dependent Variable:
* This is the variable that is *measured* or observed in the experiment.
* It is the "effect" in a cause-and-effect relationship.
* The dependent variable is what you are looking for a change in.
* Example: In the plant growth experiment, the dependent variable is the *height of the plants*.
3. Controlled Variables:
* These are all the other factors that could potentially affect the outcome of the experiment but need to be kept *constant* to isolate the effect of the independent variable.
* They are factors that you don't want to change and that could skew your results.
* Example: In the plant growth experiment, controlled variables might include:
* The type of plant used
* The amount of water given
* The temperature of the environment
* The amount of sunlight received
Here's a simple example:
* Experiment: Testing the effect of different types of music on plant growth.
* Independent Variable: The type of music played (e.g., classical, rock, pop)
* Dependent Variable: Plant height
* Controlled Variables:
* The type of plant
* The amount of water
* The amount of light
* The temperature
It's important to keep in mind that a well-designed experiment focuses on isolating the effect of the independent variable on the dependent variable. By carefully controlling other variables, scientists can draw more confident conclusions about the relationship between the variables being studied.
