scientific method

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The principles and empirical processes of discovery and demonstration considered characteristic of or necessary for scientific investigation, generally involving the observation of phenomena, the formulation of a hypothesis concerning the phenomena, experimentation to demonstrate the truth or falseness of the hypothesis, and a conclusion that validates or modifies the hypothesis.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun sciences A method of discovering knowledge about the natural world based in making falsifiable predictions (hypotheses), testing them empirically, & developing theories that match known data from repeatable physical experimentation.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a method of investigation involving observation and theory to test scientific hypotheses