Models of scientific inquiry
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A model of scientific inquiry has two functions, first, to provide a descriptive account of how scientific inquiry is carried out in practice, second, to provide an explanatory account of why scientific inquiry succeeds as well as it appears to do in arriving at genuine knowledge of its objects.
The search for scientific knowledge extends far back into antiquity. At some point in the past, at least by the time of Aristotle, philosophers recognized that a fundamental distinction should be drawn between two kinds of scientific knowledge � roughly, knowledge that and knowledge why. It is one thing to know that each planet periodically reverses the direction of its motion with respect to the background of fixed stars; it is quite a different matter to know why. Knowledge of the former type is descriptive; knowledge of the latter type is explanatory. It is explanatory knowledge that provides scientific understanding of the world. (Salmon, 1990)
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Accounts of scientific inquiry
Classical model
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.
Pragmatic model
- Main article : Pragmatic theory of truth
Logical empiricism
Wesley Salmon (1990) began his historical survey of scientific explanation with what he called the received view, as it was received from Hempel and Oppenheim in the years beginning with their "Studies in the Logic of Explanation" (1948) and culminating in Hempel's "Aspects of Scientific Explanation" (1965). Salmon summed up his analysis of these developments by means of the following Table.
| Laws \ Explananda | Particular Facts | General Regularities |
|---|---|---|
| Universal Laws | D-N Deductive-Nomological | D-N Deductive-Nomological |
| Statistical Laws | I-S Inductive-Statistical | D-S Deductive-Statistical |
In this classification, a deductive-nomological (D-N) explanation of an occurrence is a valid deduction whose conclusion states that the outcome to be explained did in fact occur. The deductive argument is called an explanation, its premisses are called the explanans (L: explaining) and the conclusion is called the explanandum (L: to be explained). Depending on a number of additional qualifications, an explanation may be ranked on a scale from potential to true.
Not all explanations in science are of the D-N type, however. An inductive-statistical (I-S) explanation accounts for an occurrence by subsuming it under statistical laws, rather than categorical or universal laws, and the mode of subsumption is itself inductive instead of deductive. The D-N type can be seen as a limiting case of the more general I-S type, the measure of certainty involved being complete, or probability 1, in the former case, whereas it is less than complete, probability < 1, in the latter case.
In this view, the D-N mode of reasoning, in addition to being used to explain particular occurrences, can also be used to explain general regularities, simply by deducing them from still more general laws.
Finally, the deductive-statistical (D-S) type of explanation, properly regarded as a subclass of the D-N type, explains statistical regularities by deduction from more comprehensive statistical laws. (Salmon 1990, pp. 8-9).
Such was the received view of scientific explanation from the point of view of logical empiricism, that Salmon says "held sway" during the third quarter of the last century (Salmon, p. 10).
See also
- Deductive-nomological
- Explanandum and explanans
- Hypothetico-deductive method
- Inquiry
- Scientific method
External links
- Adapted from the Wikipedia article, "Models_of_scientific_inquiry" http://en.wikipedia.org/wiki/Models_of_scientific_inquiry, used under the GNU Free Documentation License.
