Q. What are Independent and dependent variables?

An experiment is a set of controlled explanation that tests a hypothesis. In a research a scientist will set up and change one variable at a time. A variable is a quantity which can have more than one value. The variable which is changed in an experiment is called the independent variable. The variable which you watch to see how it changes as a result of your changes to the independent variable is called the dependent variable. For instance if you wanted to test the effect of fertilizer on plant growth you would change the amount of fertilizer applied to the same kinds of plants. The quantity of fertilizer applied would be the independent variable in this experiment. Plant growth would be the dependent variable. Several experiments also include a control which is a standard for comparison in this case plants to which no fertilizer is applied.