A model of explanation associated especially with German logician Carl Gustav Hempel (1905-1997), who regarded it as adequate for all types of explanation.
Basically a statement is explained if it is derived from a set of laws together with certain factual statements, as we might explain 'Fido barks' by saying 'All dogs bark and Fido is a dog'.
The laws must be true general statements, and subject to certain restrictions to exclude accidental 'explanations' like 'Fido barks because he is a pet of mine and all my pets (as it happens) bark'.
The laws, however -though general (for example not mentioning particular objects) - need not be universal, and the derivation of the conclusion may be inductive and not deductive; explanations can be statistical or probabilistic as well as 'deductive-nomological'.
Problems concern the scope of the theory, what restrictions must be placed on the relevant general statements, and the relevance of background knowledge.
C G Hempel, Aspects of Scientific Explanation (1965), ch. 12