Scientific theory. A scientific theory is a well-tested, broad explanation of an aspect that can be repeatedly tested and verified in accordance with scientific method, using verified protocols of observation, measurement, and evaluation of the results. Where possible, theories are tested under controlled conditions in an experiment. In everyday life, we often use the word theory to mean a hypothesis or educated guess, but a theory in the context of science is not simply a guess—it is an explanation based on extensive and repeated experimentation.
