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 gathering observable, empirical, measurable evidence, subject to the principles of reasoning[1].
Although procedures vary from one field of inquiry to another, there are identifiable features that distinguish scientific inquiry from other methods of developing knowledge. 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 wider domains of inquiry serve to bind more specific hypotheses together in a coherent structure. 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. 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. The scientific method also may involve attempts, if possible and appropriate, to achieve control over the factors involved in the area of inquiry, which may in turn be manipulated to test new hypotheses in order to gain further knowledge.
Contents [hide]
1 Elements of scientific method
1.1 DNA example
1.2 Characterizations
1.2.1 DNA/characterizations
1.2.2 Precession of Mercury
1.3 Hypothesis development
1.3.1 DNA/hypotheses
1.4 Predictions from the hypotheses
1.4.1 DNA/predictions
1.4.2 General relativity
1.5 Experiments
1.5.1 DNA/experiments
2 Evaluation and iteration
2.1 Testing and improvement
2.1.1 DNA/iterations
2.2 Confirmation
3 Models of scientific inquiry
3.1 Classical model
3.2 Pragmatic model
3.3 Computational approaches
4 Philosophy and sociology of science
5 Communication, community, culture
5.1 Peer review evaluation
5.2 Documentation and replication
5.3 Dimensions of practice
6 History
7 Notes and references
8 Further reading
9 See also
9.1 Synopsis of related topics
9.2 Logic, mathematics, methodology
9.3 Problems and issues
9.4 History, philosophy, sociology
10 External links
10.1 Science treatments
10.2 Alternative scientific treatments
10.3 Humor
[edit] Elements of scientific method
"Science is a way of thinking much more than it is a body of knowledge."[2] - Carl Sagan
". . .science consists in grouping facts so that general laws or conclusions may be drawn from them." - Charles Darwin
There are multiple ways of outlining the basic method shared by all of the fields of scientific inquiry. The following examples 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, each of which are subject only to marginal disagreements about a few very specific aspects.
The scientific method involves the following basic facets:
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.
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. This requirement, one of the most frequently contended, leads to the following: All hypotheses and theories are in principle subject to disproof. Thus, there is a point at which 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.
Causal explanation. Many scientists and theorists on scientific method argue that concepts of causality are not obligatory to science, but are in fact well-defined only under particular, admittedly widespread conditions. Under these conditions 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 in time.
The following is a more specific and technical description of the hypothesis/testing method, discussion of which follows below. This general set of elements and organization of procedures will in general tend to be more characteristic of natural sciences and experimental psychology than of disciplines such as sociology and a number of other fields commonly categorized as social sciences. Among the latter, methods of verification and testing of hypotheses may involve less stringent mathematical and statistical interpretations of these elements within the respective disciplines. Nonetheless the cycle of hypothesis, verification and formulation of new hypotheses will tend to resemble the basic cycle described below.
The essential elements of a scientific method are iterations, recursions, interleavings, and orderings of the following:
Characterizations (Quantifications, observations, and measurements)
Hypotheses (theoretical, hypothetical explanations of observations and measurements)
Predictions (reasoning including logical deduction from hypothesis and theory)
Experiments (tests of all of the above)
The element of observation includes both unconditioned observations (prior to any theory) as well as the observation of the experiment and its results. The element of experimental design must consider the elements of hypothesis development, prediction, and the effects and limits of observation because all of these elements are typically necessary for a valid experiment.
Imre Lakatos and Thomas Kuhn had done extensive work on the "theory laden" character of observation. Kuhn (1961) maintained that the scientist generally has a theory in mind before designing and undertaking experiments so as to make empirical observations, and that the "route from theory to measurement can almost never be travelled backward". This perspective implies that the way in which theory is tested is dictated by the nature of the theory itself which led Kuhn (1961, p. 166) to argue that "once it has been adopted by a profession ... no theory is recognized to be testable by any quantitative tests that it has not already passed".
Each element of scientific method is subject to peer review for possible mistakes. These activities do not describe all that scientists do (see below) but apply mostly to experimental sciences (e.g., physics, chemistry). The elements above are often taught in the educational system.[3]
The scientific method is not a recipe: it requires intelligence, imagination, and creativity. Further, it is an ongoing cycle, constantly developing more useful, accurate and comprehensive models and methods. For example, when Einstein developed the Special and General Theories of Relativity, he did not in any way refute or discount Newton's Principia. On the contrary, if one reduces out the astronomically large, the vanishingly small, and the extremely fast from Einstein's theories — all phenomena that Newton could not have observed — one is left with Newton's equations. Einstein's theories are expansions and refinements of Newton's theories, and the observations that increase our confidence in them also increase our confidence in Newton's approximations to them.
The Keystones of Science project, sponsored by the journal Science, has selected a number of scientific articles from that journal and annotated them, illustrating how different parts of each article embody the scientific method. Here is an annotated example of the scientific method example titled Microbial Genes in the Human Genome: Lateral Transfer or Gene Loss?.
A linearized, pragmatic scheme of the four points above is sometimes offered as a guideline for proceeding:
Define the question
Gather information and resources
Form hypothesis
Perform experiment and collect data
Analyze data
Interpret data and draw conclusions that serve as a starting point for new hypotheses
Publish results
The iterative cycle inherent in this step-by-step methodology goes from point 3 to 6 back to 3 again.
While this schema outlines a typical hypothesis/testing method,[4] it should also be noted that a number of philosophers, historians and sociologists of science (perhaps most notably Paul Feyerabend) claim that such descriptions of scientific method have little relation to the ways science is actually practiced.