The scientific method has four steps1.

Science, Biology and the Scientific method

8. Explain the steps of the scientific method

Advances in logic and probability held out promise of thepossibility of elaborate reconstructions of scientific theories andempirical methods. The best example of this is RudolfCarnap’s The Logical Structure of the World (1928)Here, Carnap attempted to show that a scientific theory could beunderstood as a formal axiomatic system—that is, alogic. Insofar as that system referred to the world, it did sobecause some of its basic sentences could be understood in terms ofobservations or operations which one could perform to test them. Therest of the theoretical system, including sentences using theoreticalor unobservable terms (like electron or force) would then either bemeaningful because they could be reduced to observations, or they hadpurely logical meanings (called analytic, like mathematicalidentities). This has been referred to as the verifiability criterionof meaning. According to the criterion, any statement not eitheranalytic or verifiable was strictly meaningless. Although the viewwas endorsed by Carnap in 1928, he would later come to see it as toorestrictive (Carnap 1956). Another familiar version of this ideais operationalism of Percy William Bridgman. In The Logic ofModern Physics (1927) Bridgman asserted that every physicalconcept could be defined in terms of the operations one would performto verify the application of that concept. Making good on theoperationalisation of a concept even as simple as length, however,can easily become enormously complex (for measuring very smalllengths, for instance) or impractical (measuring large distances likelight years.)

9. Describe the elements of good scientific research

Mill, in his System of Logic, puts forward instead anarrower view of induction as the essence of scientific method. ForMill, induction is the search first for regularities amongevents. Among those regularities, some will continue to hold forfurther observations, eventually gaining the status of laws. One canalso look for regularities among the laws discovered in one domain,i.e., for a law of laws. Which “law law” will hold is timeand discipline dependent and should be held open to revision. Oneexample is the Law of Universal Causation, and Mill put forwardspecific methods for identifying causes—now commonly known asMill’s methods. These five methods look for circumstances whichare common among the phenomena of interest, those which are absentwhen the phenomena are, or those for which both varytogether. Mill’s methods are still seen as capturing basicintuitions about experimental methods for finding the relevantexplanatory factors (System of Logic (1843), see entry). The methods advocated by Whewell and Mill, in the end, look similar. Both involve induction and generalization to covering laws. They differ dramatically, however, with respect to the necessity of the knowledge arrived at; that is, at the meta-methodological level (see the entries on and entries).

Carl Hempel’s (1950, 1951) criticisms of the verifiabilitycriterion of meaning had enormous influence. He pointed out thatuniversal generalizations, such as most scientific laws, were notstrictly meaningful on the criterion. Verifiability andoperationalism both seemed too restrictive to capture standardscientific aims and practice. And the tenuous connection betweenthese reconstructions and actual scientific practice was criticizedin another way. In both approaches, what are scientific methods areinstead recast in methodological roles. Measurements, for example,were looked to as ways of giving meanings to terms. The aim of thephilosopher of science was not to understand the methods perse, but to use them to reconstruct theories, their meanings, andtheir relation to the world. When scientists perform theseoperations, however, they will not report that they are doing them togive meaning to terms in a formal axiomatic system. This disconnectbetween methodology and the details of actual scientific practicewould seem to violate the empiricism the Logical Positivists, orBridgman, were committed to. The view that methodology shouldcorrespond to practice (to some extent) has been called historicism,or intuitionism. We turn to these criticisms and responsesin .[]


Hypotheses are reasoned and informed explanations.

During the Scientific Revolution these various strands of argument,experiment, and reason were forged into a dominant epistemicauthority. The 16th–18th centuries werea period of not only dramatic advance in knowledge about theoperation of the natural world—advances in mechanical, medical,biological, political, economic explanations—but also ofself-awareness of the revolutionary changes taking place, and intensereflection on the source and legitimation of the method by which theadvances were made. The struggle to establish the new authorityincluded methodological moves. The Book of Nature, according to themetaphor of Galileo Galilei (1564–1642) or Francis Bacon(1561–1626), was written in the language of mathematics, ofgeometry and number. This motivated an emphasis on mathematicaldescription and mechanical explanation as important aspects ofscientific method. Through figures such as Henry More and RalphCudworth, a neo-Platonic emphasis on the importance of metaphysicalreflection on nature behind appearances, particularly regarding thespiritual as a complement to the purely mechanical, remained animportant methodological thread of the Scientific Revolution (seethe entries on ; ; ; ).

Hypotheses cannot become theories and theories cannot become laws.

We have also tried to point out some of thecriteria and practices developed by scientists to reduce the influence ofindividual or social bias on scientific findings.

A scientific hypothesis/idea must be falsifiable

The kind of image Kuhn wanted to transform was thea-historical, rational reconstruction sought by many of the LogicalPositivists, though Carnap and other positivists were actually quite sympatheticto Kuhn’s views. (See the entry on the). Kuhn shares with other of his contemporaries, such as Feyerabend andLakatos, a commitment to a more empirical approach to philosophy ofscience. Namely, the history of science provides important data,and necessary checks, for philosophy of science, including any theoryof scientific method.