By knowing the steps of the scientific method, you can better For example, a researcher might ask a question about the relationship between. A hypothesis is an educated guess about the answer to a problem or question. A hypothesis is testable using the scientific method of problem solving. Usually. It is from Chapter 1 – The Nature of Research and Science, in the book, these two theoretical generalizations each indicate the relation between two concepts, .
This section does not cite any sources. Please help improve this section by adding citations to reliable sources. Unsourced material may be challenged and removed. October Learn how and when to remove this template message Typically for any theory to be accepted within most academia there is one simple criterion. The essential criterion is that the theory must be observable and repeatable. The aforementioned criterion is essential to prevent fraud and perpetuate science itself. The tectonic plates of the world were mapped in the second half of the 20th century.
Plate tectonic theory successfully explains numerous observations about the Earth, including the distribution of earthquakes, mountains, continents, and oceans. The defining characteristic of all scientific knowledge, including theories, is the ability to make falsifiable or testable predictions. The relevance and specificity of those predictions determine how potentially useful the theory is.
A would-be theory that makes no observable predictions is not a scientific theory at all. Predictions not sufficiently specific to be tested are similarly not useful. In both cases, the term "theory" is not applicable. A body of descriptions of knowledge can be called a theory if it fulfills the following criteria: It makes falsifiable predictions with consistent accuracy across a broad area of scientific inquiry such as mechanics. It is well-supported by many independent strands of evidence, rather than a single foundation.
It is consistent with preexisting experimental results and at least as accurate in its predictions as are any preexisting theories. Other criteria[ edit ] In addition, scientists prefer to work with a theory that meets the following qualities: It can be subjected to minor adaptations to account for new data that do not fit it perfectly, as they are discovered, thus increasing its predictive capability over time. This is because for each accepted explanation of a phenomenon, there may be an extremely large, perhaps even incomprehensible, number of possible and more complex alternatives, because one can always burden failing explanations with ad hoc hypotheses to prevent them from being falsified; therefore, simpler theories are preferable to more complex ones because they are more testable.
The formal scientific definition of theory is quite different from the everyday meaning of the word. It refers to a comprehensive explanation of some aspect of nature that is supported by a vast body of evidence. Many scientific theories are so well established that no new evidence is likely to alter them substantially. For example, no new evidence will demonstrate that the Earth does not orbit around the sun heliocentric theoryor that living things are not made of cells cell theorythat matter is not composed of atoms, or that the surface of the Earth is not divided into solid plates that have moved over geological timescales the theory of plate tectonics One of the most useful properties of scientific theories is that they can be used to make predictions about natural events or phenomena that have not yet been observed.
A scientific theory is a well-substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experiment. Such fact-supported theories are not "guesses" but reliable accounts of the real world. The theory of biological evolution is more than "just a theory". It is as factual an explanation of the universe as the atomic theory of matter or the germ theory of disease.
Our understanding of gravity is still a work in progress. But the phenomenon of gravity, like evolution, is an accepted fact. Note that the term theory would not be appropriate for describing untested but intricate hypotheses or even scientific models. The first observation of cellsby Robert Hookeusing an early microscope. The scientific method involves the proposal and testing of hypothesesby deriving predictions from the hypotheses about the results of future experiments, then performing those experiments to see whether the predictions are valid.
This provides evidence either for or against the hypothesis.
Scientific theory - Wikipedia
When enough experimental results have been gathered in a particular area of inquiry, scientists may propose an explanatory framework that accounts for as many of these as possible. This explanation is also tested, and if it fulfills the necessary criteria see abovethen the explanation becomes a theory.
This can take many years, as it can be difficult or complicated to gather sufficient evidence. Once all of the criteria have been met, it will be widely accepted by scientists see scientific consensus as the best available explanation of at least some phenomena.
It will have made predictions of phenomena that previous theories could not explain or could not predict accurately, and it will have resisted attempts at falsification. The strength of the evidence is evaluated by the scientific community, and the most important experiments will have been replicated by multiple independent groups. Theories do not have to be perfectly accurate to be scientifically useful. For example, the predictions made by classical mechanics are known to be inaccurate in the relatistivic realm, but they are almost exactly correct at the comparatively low velocities of common human experience.
For example, certain tests may be unfeasible or technically difficult. As a result, theories may make predictions that have not yet been confirmed or proven incorrect; in this case, the predicted results may be described informally with the term "theoretical".
These predictions can be tested at a later time, and if they are incorrect, this may lead to the revision or rejection of the theory. Modification and improvement[ edit ] If experimental results contrary to a theory's predictions are observed, scientists first evaluate whether the experimental design was sound, and if so they confirm the results by independent replication.
A search for potential improvements to the theory then begins. Solutions may require minor or major changes to the theory, or none at all if a satisfactory explanation is found within the theory's existing framework.
Since each new version of a theory or a completely new theory must have more predictive and explanatory power than the last, scientific knowledge consistently becomes more accurate over time.
If modifications to the theory or other explanations seem to be insufficient to account for the new results, then a new theory may be required. Since scientific knowledge is usually durable, this occurs much less commonly than modification. This is because it is still the best available explanation for many other phenomena, as verified by its predictive power in other contexts. For example, it has been known since that the observed perihelion precession of Mercury violates Newtonian mechanics,  but the theory remained the best explanation available until relativity was supported by sufficient evidence.
Also, while new theories may be proposed by a single person or by many, the cycle of modifications eventually incorporates contributions from many different scientists.
If a theory does not require modification despite repeated tests, this implies that the theory is very accurate. This also means that accepted theories continue to accumulate evidence over time, and the length of time that a theory or any of its principles remains accepted often indicates the strength of its supporting evidence.
Unification[ edit ] In quantum mechanicsthe electrons of an atom occupy orbitals around the nucleus. This image shows the orbitals of a hydrogen atom s, p, d at three different energy levels 1, 2, 3. Brighter areas correspond to higher probability density. In some cases, two or more theories may be replaced by a single theory that explains the previous theories as approximations or special cases, analogous to the way a theory is a unifying explanation for many confirmed hypotheses; this is referred to as unification of theories.
For example, physical theories in the 19th century implied that the Sun could not have been burning long enough to allow certain geological changes as well as the evolution of life. This was resolved by the discovery of nuclear fusionthe main energy source of the Sun. For example, atomic theory is an approximation of quantum mechanics. Current theories describe three separate fundamental phenomena of which all other theories are approximations;  the potential unification of these is sometimes called the Theory of Everything.
Relativity[ edit ] InAlbert Einstein published the principle of special relativitywhich soon became a theory. He thereby duplicated the Lorentz transformation and the Lorentz contraction that had been hypothesized to resolve experimental riddles and inserted into electrodynamic theory as dynamical consequences of the aether's properties.
An elegant theory, special relativity yielded its own consequences,  such as the equivalence of mass and energy transforming into one another and the resolution of the paradox that an excitation of the electromagnetic field could be viewed in one reference frame as electricity, but in another as magnetism.
Einstein sought to generalize the invariance principle to all reference frames, whether inertial or accelerating.
InEinstein's equivalence principle implied that a free fall within a uniform gravitational field is equivalent to inertial motion. Even massless energy exerts gravitational motion on local objects by "curving" the geometrical "surface" of 4D space-time.
Yet unless the energy is vast, its relativistic effects of contracting space and slowing time are negligible when merely predicting motion. Although general relativity is embraced as the more explanatory theory via scientific realismNewton's theory remains successful as merely a predictive theory via instrumentalism.
To calculate trajectories, engineers and NASA still uses Newton's equations, which are simpler to operate. Scientific law Both scientific laws and scientific theories are produced from the scientific method through the formation and testing of hypotheses, and can predict the behavior of the natural world. Theories are supported by evidence from many different sources, and may contain one or several laws.
A theory does not change into a scientific law with the accumulation of new or better evidence. A theory will always remain a theory; a law will always remain a law.
Unlike hypotheses, theories and laws may be simply referred to as scientific fact. First-order logic is an example of a formal language. The logical positivists envisaged a similar scientific language. In addition to scientific theories, the language also included observation sentences "the sun rises in the east"definitions, and mathematical statements. The phenomena explained by the theories, if they could not be directly observed by the senses for example, atoms and radio waveswere treated as theoretical concepts.
In this view, theories function as axioms: However, the predictions are then tested against reality to verify the theories, and the "axioms" can be revised as a direct result. The phrase " the received view of theories " is used to describe this approach. Terms commonly associated with it are " linguistic " because theories are components of a language and " syntactic " because a language has rules about how symbols can be strung together. Problems in defining this kind of language precisely, e.
Theories as models[ edit ] Main article: Scientific model The semantic view of theorieswhich identifies scientific theories with models rather than propositionshas replaced the received view as the dominant position in theory formulation in the philosophy of science. Positivists also advocate the use of some types of secondary data, particularly official statistics. They argue that human behaviour is not the result of external social laws.
Society is the product of interaction — meaning when people come together in social groups. The way people interpret these social interactions is centrally important to the understanding of social behaviour.
Interpretivists prefer methods such as unstructured interviews and observation because these uncover the meanings behind action and emphasise validity. Such methods attempt to see the social world through the eyes of the people who inhabit it by studying their everyday life verstehen or by letting those being studied speak for themselves. Practical constraints on choice of method In addition to the theoretical, there are also practical reasons why a particular research method might be chosen.
Funding — if the sociologist does not have access to large funds, a cheap method will be required. Secondary data is cheap because it has already been collected. Postal questionnaires are cheaper than interviews, which are probably cheaper than observation studies. Time — if you have years, observation may be possible.
The subject matter is going to influence choice of research. For example, research into trends may suit quantitative research whilst research into attitudes may suit qualitative methods.
Relationships between Theory & Methods
The research population may not be accessible because it is regarded as deviant and may feel threatened. If this is the case, covert observation may be necessary.
The research population may be geographically dispersed. If it is, a postal questionnaire may be necessary, especially if money is tight. Ethical considerations There are some generally agreed professional guidelines which are followed in social research.