Scientific method - 1 Scientific method is a body of techniques for investigating phenomena and acquiring new knowledge, as well as for correcting and integrating previous knowledge. It is based on observable, empirical, measurable evidence, and subject to laws of reasoning. Although specialized procedures vary from one field of inquiry to another, there are identifiable features that distinguish scientific inquiry from other methods of developing knowledge.

Scientific method - 2 Scientific researchers propose specific hypotheses as explanations of natural phenomena, and design experimental studies that test these predictions for accuracy. These steps are repeated in order to make increasingly dependable predictions of future results. Theories that encompass whole domains of inquiry serve to bind more specific hypotheses together into logically coherent wholes.

Scientific method - 3 This in turn aids in the formation of new hypotheses, as well as in placing groups of specific hypotheses into a broader context of understanding. Among other facets shared by the various fields of inquiry is the conviction that the process must be objective so that the scientist does not bias the interpretation of the results or change the results outright.

Scientific method - 4 Another basic expectation is that of making complete documentation of data and methodology available for careful scrutiny by other scientists and researchers, thereby allowing other researchers the opportunity to verify results by attempted reproduction of them. This also allows statistical measures of the reliability of the results to be established.

Scientific method - 5 There are multiple ways of outlining the basic method shared by all of the fields of scientific inquiry. The following facets are typical classifications of the most important components of the method on which there is very wide agreement in the scientific community and among philosophers of science.

Scientific method - 6 Observation. A constant feature of scientific inquiry. Description. Information must be reliable, i.e., replicable (repeatable) as well as valid (relevant to the inquiry). Prediction. Information must be valid for observations past, present, and future of given phenomena, i.e., purported "one shot" phenomena do not give rise to the capability to predict, nor to the ability to repeat an experiment.

Scientific method - 7 Control. Actively and fairly sampling the range of possible occurrences, whenever possible and proper, as opposed to the passive acceptance of opportunistic data, is the best way to control or counterbalance the risk of empirical bias. Falsifiability, or the elimination of plausible alternatives. This is a gradual process that requires repeated experiments by multiple researchers who must be able to replicate results in order to corroborate them.

Scientific method - 8 All hypotheses and theories are in principle subject to disproof. There might be a consensus about a particular hypothesis or theory, yet it must in principle remain tentative. As a body of knowledge grows and a particular hypothesis or theory repeatedly brings predictable results, confidence in the hypothesis or theory increases.

Scientific method - 9 Causal explanation. The following requirements are generally regarded as important to scientific understanding: Identification of causes. Identification of the causes of a particular phenomenon to the best achievable extent. Covariation of events. The hypothesized causes must correlate with observed effects. Time-order relationship. The hypothesized causes must precede the observed effects.

Scientific method - 10 Testability, a property applying to an empirical hypothesis, involves two components: The logical property described as contingency, defeasibility, or falsifiability, meaning that counterexamples to the hypothesis are not logically impossible. The practical feasibility of observing a reproducible series of such counterexamples, if they do exist. In short, a hypothesis is testable if there is some real hope of deciding whether it is true or false of real experience.

Scientific method - 11 The predictive power of a scientific theory refers to its ability to generate testable predictions. Theories with strong predictive power are highly valued, because the predictions can often encourage the falsification of the theory. The concept of predictive power differs from explanatory or descriptive power (where phenomena that are already known are retrospectively explained by a given theory) in that it allows a prospective test of theoretical understanding.

Scientific method - 12 Scientific ideas that do not confer any predictive power are considered at best "conjectures", or at worst "pseudoscience". Because they cannot be tested or falsified in any way, there is no way to determine whether they are true or false, and so they do not gain the status of "scientific theory". Theories whose "predictive power" presupposes technologies that are not currently possible constitute something of a grey area.

Scientific method - 13 Reproducibility is one of the main principles of the scientific method, and refers to the ability of a test or experiment to be accurately reproduced, or replicated. The term is very closely related to the concept of testability and, depending on the particular field, may require the test or experiment to be falsifiable.

Scientific method - 14 The results of an experiment performed by a group of researchers are generally evaluated by other independent researchers by reproducing the original experiment. They repeat the same experiment themselves, based on the original experimental description, and see if their experiment gives similar results to those reported by the original group. The result values are said to be commensurate if they are obtained (in distinct experimental trials) according to the same reproducible experimental description and procedure.

Scientific method - 15 Experiments which cannot be reliably reproduced are generally not considered to provide useful scientific evidence. Results which prove to be highly reproducible are given more credence than those which are less reproducible, although this is based on an intuitive application of the principle of induction, rather than on the strict application of the principles of falsifiability.