Independent variable – the variable that is altered during a scientific experiment.
Dependent variable – the variable being tested or measured during a scientific experiment.
Controlled variable – a variable that is kept the same during a scientific experiment. Any change in a controlled variable would invalidate the results.
Example
Practical B2 - investigating the energy content of food
Independent variable – food sample.
Dependent variable – temperature increase of the water.
Controlled variables – mass of food, mass of water and distance of food to water.
