Scientific method

Scientific method is the way that scientists investigate phenomena and acquire new knowledge. It is based on observable, empirical, measurable evidence, and subject to laws of reasoning. Scientists propose hypotheses to explain phenomena, and design experimental studies to test these. Theories that encompass whole domains of inquiry bind hypotheses together into logically coherent wholes. This aids in formulating new hypotheses, as well as in placing groups of hypotheses into a broader context.

Elements of scientific method

"Science is a way of thinking much more than it is a body of knowledge." (Carl Sagan).

". . .science consists in grouping facts so that general laws or conclusions may be drawn from them." (Charles Darwin)

The scientific method involves:

• 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, All hypotheses and theories are in principle subject to disproof.
• 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
• 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 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 hypotheses and theories)
• Experiments (tests of all of the above)

The element of observation includes both unconditioned observations (before 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. These activities do not describe all that scientists do (see below) but apply mostly to experimental sciences (e.g., physics, chemistry).

The scientific method 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 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.

A linearized, pragmatical scheme of the four above points is sometimes offered as a guideline for proceeding:

While this schema outlines a typical hypothesis/testing method, some 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.

DNA example

Each element of scientific method is illustrated below by an example from the discovery of the structure of DNA:

• DNA/characterizations
• DNA/hypotheses
• DNA/predictions
• DNA/experiments

Characterizations

The scientific method depends upon increasingly more sophisticated characterizations of subjects of the investigation. (The subjects can also be called lists of unsolved problems or the unknowns.) For example, Benjamin Franklin correctly characterized St. Elmo's fire as electrical in nature, but it has taken many experiments and theory to establish this.

Scientific measurements taken are usually tabulated, graphed, or mapped, and statistical analyses of them. The measurements might be made in a controlled setting, such as a laboratory, or made on more or less inaccessible or unmanipulatable objects such as stars or human populations. The measurements often require specialized scientific instruments such as thermometers, spectroscopes, or voltmeters, and the progress of a scientific field is usually intimately tied to their invention and development.

Measurements also demand the use of operational definitions of relevant quantities. That is, a scientific quantity is described or defined by how it is measured, as opposed to some more vague, inexact or "idealized" definition. For example, electrical current, measured in amperes, may be operationally defined in terms of the mass of silver deposited in a certain time on an electrode in an electrochemical device that is described in some detail. The operational definition of a thing often relies on comparisons with standards: the operational definition of "mass" ultimately relies on the use of an artifact, such as a certain kilogram of platinum-iridium kept in a laboratory in France.

The scientific definition of a term sometimes differs substantially from their natural language usage. For example, mass and weight overlap in meaning in common discourse, but have distinct meanings in physics. Scientific quantities are often characterized by their units of measure which can later be described in terms of conventional physical units when communicating the work.

Measurements are also usually accompanied by estimates of their uncertainty. The uncertainty is often estimated by making repeated measurements. Uncertainties may also be calculated by consideration of the uncertainties of the individual underlying quantities that are used. Counts of things, such as the number of people in a nation at a particular time, may also have an uncertainty due to limitations of the method used. Counts may only represent a sample of desired quantities, with an uncertainty that depends upon the sampling method used and the number of samples taken.

New theories sometimes arise upon realizing that certain terms had not previously been sufficiently clearly defined. For example, Albert Einstein's first paper on relativity begins by defining simultaneity and the means for determining length. These ideas were skipped over by Isaac Newton with, "I do not define time, space, place and motion, as being well known to all." Einstein's paper then demonstrates that they (viz., absolute time and length independent of motion) were approximations. Francis Crick cautions us that when characterizing a subject, however, it can be premature to define something when it remains ill-understood. In Crick's study of consciousness, he actually found it easier to study awareness in the visual system, rather than to study Free Will, for example. His cautionary example was the gene; the gene was much more poorly understood before Watson and Crick's pioneering discovery of the structure of DNA; it would have been counterproductive to spend much time on the definition of the gene, before them.

DNA/characterizations

The history of the discovery of the structure of DNA is a classic example of the elements of scientific method: in 1950 it was known that genetic inheritance had a mathematical description, starting with the studies of Gregor Mendel, but the mechanism was unclear. Researchers in Bragg's laboratory at Cambridge University made X-ray diffraction pictures of various molecules, starting with crystals of salt, and proceeding to more complicated substances. Using clues painstakingly assembled over the course of decades, beginning with its chemical composition, it was determined that it should be possible to characterize the physical structure of DNA, and the X-ray images would be the vehicle.

Precession of Mercury

Precession of the perihelion (very exaggerated)

The characterization element can require extended and extensive study. It took thousands of years of measurements, from the Chaldean, Indian, Persian, Greek, Arabic and European astronomers, to record the motion of planet Earth. Newton condensed these measurements into consequences of his laws of motion, but the perihelion of the planet Mercury's orbit exhibits a precession which is not fully explained by Newton's laws of motion. The observed difference for Mercury's precession, between Newtonian theory and relativistic theory (approximately 43 arc-seconds per century), was one of the things that occurred to Einstein as a possible early test of his theory of General Relativity.

Hypothesis development

A hypothesis is a suggested explanation of a phenomenon, or a reasoned proposal suggesting a possible correlation between or among a set of phenomena. Hypotheses may have the form of a mathematical model, or they can be formulated as existential statements, stating that some particular instance of the phenomenon being studied has some characteristic and causal explanations, which have the general form of universal statements, stating that every instance of the phenomenon has a particular characteristic.

Scientists are free to use whatever resources they have — their own creativity, ideas from other fields, induction, Bayesian inference, and so on — to imagine possible explanations for a phenomenon under study. Charles Sanders Peirce described the incipient stages of inquiry, instigated by the "irritation of doubt" to venture a plausible guess, as abductive reasoning. The history of science is filled with stories of scientists claiming a "flash of inspiration", or a hunch, which then motivated them to look for evidence to support or refute their idea. Michael Polanyi made such creativity the centrepiece of his discussion of methodology.

Karl Popper argued that a hypothesis must be falsifiable, and that a proposition or theory cannot be called scientific if it does not admit the possibility of being shown false. It must at least in principle be possible to make an observation that would show the proposition to be false, even if that observation had not yet been made.

William Glen observes that

the success of a hypothesis, or its service to science, lies not simply in its perceived "truth", or power to displace, subsume or reduce a predecessor idea, but perhaps more in its ability to stimulate the research that will illuminate … bald suppositions and areas of vagueness.

In general, scientists tend to look for theories that are "elegant" or "beautiful". In contrast to the usual English use of these terms, they here refer to a theory in accordance with the known facts, which is nevertheless relatively simple and easy to handle. If a model is mathematically too complicated, it is hard to deduce any prediction. Note that 'simplicity' may be perceived differently by different individuals and cultures.

DNA/hypotheses

Linus Pauling proposed that DNA was a triple helix. Francis Crick and James Watson learned of Pauling's hypothesis, understood from existing data that Pauling was wrong and realized that Pauling would soon realize his mistake. So the race was on to figure out the correct structure. Except that Pauling did not realize at the time that he was in a race!

Predictions from the hypotheses

Any useful hypothesis will enable predictions, by reasoning including deductive reasoning. It might predict the outcome of an experiment in a laboratory setting or the observation of a phenomenon in nature. The prediction can also be statistical and only talk about probabilities.

DNA/predictions

When Watson and Crick hypothesized that DNA was a double helix, Francis Crick predicted that an X-ray diffraction image of DNA would show an X-shape. Also in their first paper they predicted that the double helix structure that they discovered would prove important in biology writing "It has not escaped our notice that the specific pairing we have postulated immediately suggests a possible copying mechanism for the genetic material".

General Relativity

Einstein's prediction (1907): Light bends in a gravitational field

Einstein's theory of General Relativity makes several specific predictions about the observable structure of space-time, such as a prediction that light bends in a gravitational field and that the amount of bending depends in a precise way on the strength of that gravitational field. Arthur Eddington's observations made during a 1919 solar eclipse supported General Relativity rather than Newtonian gravitation.

Experiments

Template:Mainarticle Once predictions are made, they can be tested by experiments. If the outcome contradicts the predictions, then the hypotheses are called into question and explanations may be sought. Sometimes experiments are conducted incorrectly. If the results confirm the predictions, then the hypotheses are considered likely to be correct but might still be wrong and are subject to further testing. Scientists assume an attitude of openness and accountability on the part of those conducting an experiment. Detailed record keeping is essential, to provide evidence of the effectiveness and integrity of the procedure and to also assist in reproducing the experimental results. This tradition can be seen in the work of Hipparchus (190 BCE - 120 BCE), when determining a value for the precession of the Earth over 2100 years ago, and 1000 years before Al-Batani.

DNA/experiments

Before proposing their model Watson and Crick had previously seen x-ray diffraction images by Rosalind Franklin, Maurice Wilkins, and Raymond Gosling. However, they later reported that Franklin initially rebuffed their suggestion that DNA might be a double helix. Franklin had immediately spotted flaws in the initial hypotheses about the structure of DNA by Watson and Crick. The X-shape in X-ray images helped confirm the helical structure of DNA.

Evaluation and iteration

The scientific process is iterative. At any stage it is possible that some consideration will lead the scientist to repeat an earlier part of the process. Failure to develop an interesting hypothesis may lead a scientist to redefine the subject they are considering. Failure of a hypothesis to produce interesting and testable predictions may lead to reconsideration of the hypothesis or of the definition of the subject. Failure of the experiment to produce interesting results may lead the scientist to reconsidering the experimental method, the hypothesis or the definition of the subject.

Other scientists may start their own research and enter the process at any stage. They might adopt the characterization and formulate their own hypothesis, or they might adopt the hypothesis and deduce their own predictions. Often the experiment is not done by the person who made the prediction and the characterization is based on experiments done by someone else. Published results of experiments can also serve as a hypothesis predicting their own reproducibility.

DNA/iterations

After considerable fruitless experimentation, being discouraged by their superior from continuing, and numerous false starts, Watson and Crick were able to infer the essential structure of DNA by concrete modelling of the physical shapes of the nucleotides which comprise it. They were guided by the bond lengths which had been deduced by Linus Pauling and the X-ray diffraction images of Rosalind Franklin.

Confirmation

Science is a social enterprise, and scientific work tends to be accepted by the community when it has been confirmed. Crucially, experimental and theoretical results must be reproduced by others within the science community. Researchers have given their lives for this vision; Georg Wilhelm Richmann was killed by lightning (1753) when attempting to replicate the 1752 kite experiment of Benjamin Franklin.

Models of scientific inquiry

The classical model of scientific inquiry derives from Aristotle, who distinguished the forms of approximate and exact reasoning, set out the threefold scheme of abductive, deductive, and inductive inference, and also treated the compound forms such as reasoning by analogy.

Charles Peirce considered scientific inquiry to be a species of the genus inquiry, which he defined as any means of fixing belief, that is, any means of arriving at a settled opinion on a matter in question. He observed that inquiry in general begins with a state of uncertainty and moves toward a state of certainty, sufficient at least to terminate the inquiry for the time being. He graded the prevalent forms of inquiry according to their evident success in achieving their common objective, scoring scientific inquiry at the high end of this scale. At the low end he placed what he called the method of tenacity, a die-hard attempt to deny uncertainty and fixate on a favored belief. Next in line he placed the method of authority, a determined attempt to conform to a chosen source of ready-made beliefs. After that he placed what might be called the method of congruity, also called the a priori, the dilettante, or the what is agreeable to reason method. Peirce observed the fact of human nature that almost everybody uses almost all of these methods at one time or another, and that even scientists, being human, use the method of authority far more than they like to admit. But what recommends the specifically scientific method of inquiry above all others is the fact that it is deliberately designed to arrive at the ultimately most secure beliefs, upon which the most successful actions can be based.

Computational approaches

Many subspecialties of applied logic and computer science, including artificial intelligence, computational learning theory, inferential statistics, and knowledge representation, are concerned with setting out computational, logical, and statistical frameworks for the various types of inference involved in scientific inquiry, in particular, hypothesis formation, logical deduction, and empirical testing. Some of these draw on measures of complexity from algorithmic information theory to guide the making of predictions from prior distributions of experience, for example, see the complexity measure called the speed prior from which a computable strategy for optimal inductive reasoning can be derived.

Philosophical issues

Scientific researchers generally express a high level of confidence in scientific method. What justifies their level of confidence that scientific method, under some conception, model, or recipe, is truly a good way to achieve the knowledge that it promises? That is a question about the grounds of validity of scientific method, also referred to as the problem of justification or warrant. While the philosophy of science has limited direct impact on day-to-day scientific practice, it plays a vital role in justifying and defending the scientific approach. There is disagreement over whether there is a single 'scientific method' or many of them.

Philosophers of science are interested in to what extent the actual practice of scientists conforms to the espoused methods or the ostensible norms, to which most of them apparently assent; some question whether scientific knowledge is actually produced by a defined, describable, or determinate methodology (see, for instance, the writings of Feyerabend and Kuhn).

We find ourselves in a world that is not directly understandable. We sometimes disagree about the facts of the things we see in the world around us, and some things in the world are at odds with our understanding. The scientific method attempts to provide a way in which we can reach agreement and understanding. A "perfect" scientific method might work in such a way that rational application of the method would always result in agreement and understanding; a perfect method would arguably be algorithmic, and not leave any room for rational agents to disagree. As with all philosophical topics, the search has been neither straightforward nor simple. Logical Positivist, empiricist, falsificationist, and other theories have claimed to give a definitive account of the logic of science, but each has been criticised.

Werner Heisenberg in a quote that he attributed to Albert Einstein many years later, stated [Heisenberg 1971]:

It is quite wrong to try founding a theory on observable magnitudes alone. In reality the very opposite happens. It is the theory which decides what we can observe. You must appreciate that observation is a very complicated process. The phenomenon under observation produces certain events in our measuring apparatus. As a result, further processes take place in the apparatus, which eventually and by complicated paths produce sense impressions and help us to fix the effects in our consciousness. Along this whole path—from the phenomenon to its fixation in our consciousness—we must be able to tell how nature functions, must know the natural laws at least in practical terms, before we can claim to have observed anything at all. Only theory, that is, knowledge of natural laws, enables us to deduce the underlying phenomena from our sense impressions. When we claim that we can observe something new, we ought really to be saying that, although we are about to formulate new natural laws that do not agree with the old ones, we nevertheless assume that the existing laws—covering the whole path from the phenomenon to our consciousness—function in such a way that we can rely upon them and hence speak of “observation”.

Considerations such as these led Feyerabend to deny that science is genuinely a methodological process. In his book Against Method he argues that scientific progress is not the result of applying any particular method. In essence, he says that "anything goes", by which he meant that for any specific methodology or norm of science, successful science has been done in violation of it. Criticisms such as his led to a rise in the study of the scientific enterprise as a social phenomenon. To the degree that sociological studies focus on cooperation and appreciation as well as conflict both within the scientific communities and beyond, however, the sociology of science is also quite capable of accounting for sociological components of the success of the scientific enterprise which for much of the 20th century had fairly widely been taken as granted. The strong programme has put forward a perspective of just this kind.

Problem of demarcation

The problem of evaluating a system of thought with regard to its status as science is often called the demarcation problem. The criteria for a system of assumptions, methods, and theories to qualify as science vary in their details from application to application, but they typically include (1) the formulation of hypotheses that meet the logical criterion of contingency, defeasibility, or falsifiability and the closely related empirical and practical criterion of testability, (2) a grounding in empirical evidence, and (3) the use of scientific method. The procedures of science typically include a number of heuristic guidelines, such as the principles of conceptual economy or theoretical parsimony that fall under the rubric of Ockham's razor. The following is a list of additional features that are highly desirable in a scientific theory.

• Consistent. Generates no obvious logical contradictions, and 'saves the phenomena', being consistent with observation.
• Parsimonious. Economical in the number of assumptions and hypothetical entities.
• Pertinent. Describes and explains observed phenomena.
• Falsifiable and testable.
• Reproducible.
• Correctable and dynamic.
• Integrative, robust, and corrigible. Subsumes previous theories as approximations, and allows possible subsumption by future theories. See Correspondence principle
• Provisional or tentative. Does not assert the absolute certainty of the theory.

Communication, community, culture

Often the scientific method is not employed by a single person, but by several cooperating directly or indirectly. Such cooperation can be regarded as one of the defining elements of a scientific community. Various techniques have been developed to ensure the integrity of the scientific method within such an environment.

Peer review evaluation

Scientific journals use a process of peer review, in which manuscripts are submitted by editors of scientific journals to (usually one to three) fellow (usually anonymous) scientists familiar with the field for evaluation. The referees may or may not recommend publication, publication with suggested modifications, or, sometimes, publication in another journal. This helps to keep the scientific literature free of unscientific work, reduces obvious errors, and generally otherwise improve the quality of the scientific literature. The peer review process has been criticised, but has been very widely adopted by the scientific community.

Documentation and replication

Sometimes experimenters may make systematic errors during their experiments, or (in rare cases) deliberately falsify their results. Consequently, it is a common practice for other scientists to attempt to repeat the experiments in order to duplicate the results, thus further validating the hypothesis. As a result, experimenters are expected to maintain detailed records of their experiments, to provide evidence of the effectiveness and integrity of the procedure and assist in reproduction. These procedural records may also assist in the conception of new experiments to test the hypothesis, and may prove useful to engineers who might examine the potential practical applications of a discovery. Note that it is not possible for a scientist to record everything that took place in an experiment. He must select the facts he believes to be relevant to the experiment and report them. This may lead to problems if some supposedly irrelevant feature is questioned. For example, Heinrich Hertz did not report the size of the room used to test Maxwell's equations, which later turned out to account for a small deviation in the results. The problem is that parts of the theory itself need to be assumed in order to select and report the experimental conditions. Observations are sometimes hence described as being 'theory-laden'.

Dimensions of practice

The primary constraints on contemporary western science are:

• Publication, i.e. Peer review
• Resources (mostly funding)

Both of these constraints indirectly bring in a scientific method — work that too obviously violates the constraints will be difficult to publish and difficult to get funded. Journals do not require submitted papers to conform to anything more specific than "good scientific practice" and this is mostly enforced by peer review. Originality, importance and interest are more important - see for example the author guidelines for Nature.

Criticisms (see Critical theory) of these restraints are that they are so nebulous in definition (e.g. "good scientific practice") and open to ideological, or even political, manipulation apart from a rigorous practice of a scientific method, that they often serve to censor rather than promote scientific discovery. Apparent censorship through refusal to publish ideas unpopular with mainstream scientists (unpopular because of ideological reasons and/or because they seem to contradict long held scientific theories) has soured the popular perception of scientists as being neutral or seekers of truth and often denigrated popular perception of science as a whole.

History

See also Timeline of the history of scientific method

The development of the scientific method is inseparable from the history of science itself. Ancient Egyptian documents, such as early papyri, describe methods of medical diagnosis. In ancient Greek culture, the first elements of the inductive scientific method clearly become well established. Significant progress in methodology was made in early Muslim philosophy, in particular using experiments to distinguish between competing scientific theories set within a generally empirical orientation. The fundamental tenets of the basic scientific method crystallized no later than the rise of the modern physical sciences, in the 17th and 18th centuries. In his work Novum Organum (1620) — a reference to Aristotle's Organon — Francis Bacon outlined a new system of logic to improve upon the old philosophical process of syllogism. Then, in 1637, René Descartes established the framework for a scientific method's guiding principles in his treatise, Discourse on Method. These writings are considered critical in the historical development of the scientific method.

In the late 19th century, Charles Sanders Peirce proposed a schema that would turn out to have considerable influence in the development of current scientific method generally. Speaking in broader context in "How to Make Our Ideas Clear" (1878) [2], Peirce outlined an objectively verifiable method to test the truth of putative knowledge on a way that goes beyond mere foundational alternatives, focusing upon both deduction and induction. He thus placed induction and deduction in a complementary rather than competitive context (the latter of which had been the primary trend at least since David Hume, who wrote in the mid-to-late 18th century). Secondly, Peirce put forth the basic schema for hypotheis/testing that continues to prevail today. Extracting the theory of inquiry from its raw materials in classical logic, he refined it in parallel with the early development of symbolic logic to address the then-current problems in scientific reasoning. Peirce examined and articulated the three fundamental modes of reasoning that, as discussed above, play a role in inquiry today, the processes currently known as abductive, deductive, and inductive inference.

Karl Popper (1902-1994), beginning in the 1930s argued that a hypothesis must be falsifiable and, following Peirce and others, that science would best progress using deductive reasoning as its primary emphasis, known as critical rationalism. His astute formulations of logical procedure helped to rein in exessive use of inductive speculation upon inductive speculation, and also strengthened the conceptual foundation for today's peer review procedures.

Notes and references

• Aristotle, "Prior Analytics", Hugh Tredennick (trans.), pp. 181-531 in Aristotle, Volume 1, Loeb Classical Library, William Heinemann, London, UK, 1938.
• Peirce CS, Essays in the Philosophy of Science, Vincent Tomas (ed.), Bobbs–Merrill, New York, NY, 1957.
• Peirce CS, "Lectures on Pragmatism", Cambridge, MA, March 26 – May 17, 1903. Reprinted in part, Collected Papers, CP 5.14–212. Reprinted with Introduction and Commentary, Patricia Ann Turisi (ed.), Pragmatism as a Principle and a Method of Right Thinking: The 1903 Harvard "Lectures on Pragmatism", State University of New York Press, Albany, NY, 1997. Reprinted, pp. 133–241, Peirce Edition Project (eds.), The Essential Peirce, Selected Philosophical Writings, Volume 2 (1893–1913), Indiana University Press, Bloomington, IN, 1998.
• Peirce, C.S., Collected Papers of Charles Sanders Peirce, vols. 1-6, Charles Hartshorne and Paul Weiss (eds.), vols. 7-8, Arthur W. Burks (ed.), Harvard University Press, Cambridge, MA, 1931-1935, 1958. Cited as CP vol.para.

Further reading

• Bacon, Francis Novum Organum (The New Organon), 1620. Bacon's work described many of the accepted principles, underscoring the importance of Theory, empirical results, data gathering, experiment, and independent corroboration.
• Bauer, Henry H., Scientific Literacy and the Myth of the Scientific Method, University of Illinois Press, Champaign, IL, 1992
• Beveridge, William I. B., The Art of Scientific Investigation, Vintage/Alfred A. Knopf, 1957.
• Bernstein, Richard J., Beyond Objectivism and Relativism: Science, Hermeneutics, and Praxis, University of Pennsylvania Press, Philadelphia, PA, 1983.
• Dewey, John, How We Think, D.C. Heath, Lexington, MA, 1910. Reprinted, Prometheus Books, Buffalo, NY, 1991.
• Feyerabend, Paul K., Against Method, Outline of an Anarchistic Theory of Knowledge, 1st published, 1975. Reprinted, Verso, London, UK, 1978.
• Heisenberg, Werner, Physics and Beyond, Encounters and Conversations, A.J. Pomerans (trans.), Harper and Row, New York, NY 1971, pp. 63–64.
• Kuhn, Thomas S., "The Function of Measurement in Modern Physical Science", ISIS 52(2), 161–193, 1961.
• Kuhn, Thomas S., The Structure of Scientific Revolutions, University of Chicago Press, Chicago, IL, 1962. 2nd edition 1970. 3rd edition 1996.
• Kuhn, Thomas S., The Essential Tension, Selected Studies in Scientific Tradition and Change, University of Chicago Press, Chicago, IL, 1977.
• Latour, Bruno, Science in Action, How to Follow Scientists and Engineers through Society, Harvard University Press, Cambridge, MA, 1987.
• McComas, William F., ed. The Principle Elements of the Nature of Science: Dispelling the Myths, from The Nature of Science in Science Education, pp53-70, Kluwer Academic Publishers, Netherlands 1998.
• Poincaré, Henri, Science and Hypothesis, 1905, Eprint
• Popper, Karl R., Unended Quest, An Intellectual Autobiography, Open Court, La Salle, IL, 1982.
• Thagard, Paul, Conceptual Revolutions, Princeton University Press, Princeton, NJ, 1992.

External links

Science treatments

• An Introduction to Science: Scientific Thinking and a scientific method by Steven D. Schafersman.
• Introduction to a scientific method
• Theory-ladenness by Paul Newall at The Galilean Library
• Scientific Method
• Analysis and Synthesis: On Scientific Method based on a study by Bernhard Riemann From the Swedish Morphological Society
• Using the scientific method for designing science fair projects from Science Made Simple

Alternative scientific treatments

• The Myth of a scientific method by Dr. Terry Halwes (A respectful essay making the point that scientists actually use a variety of methods that cannot be easily reduced to a single coherent methodology.)
• The Test Case As A Scientific Experiment (An article that compares the scientific method and software testing)
• The Scientific Principle - a simplistic overview

Humor

• Updated Scientific Method