Factors that remain constant from experiment to experiment are the constants.
Explanation:
A constant in an experiment is also known as a <em>control variable</em>. It is the part of an experiment that must stay the same in order to validate the experiment. If the constant were to change, the results would be skewed and therefore false.
i.e. you want to test the rate of growth of lima bean plants in different types of lighting. You believe that a lima bean plant that grows in yellow will grow faster and stronger than a lima bean plant that grows in blue or red light.
In this experiment, the constant would be the lima bean plant. You cannot change the type of seed or else your experiment is invalidated. If you tried to use a sunflower seed in the blue lighting and a tomato seed in the red lighting, your results would be invalidated and skewed.
