Validity

:This article discusses validity in logic, for the term in the social sciences see validity (psychometric).

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

In a logical argument, the term validity is used to determine whether a form of an argument meets a certain set of standards to be deemed valid. An argument is said to be valid if, for every model (m), all premises are true in (m), then the conclusion is true in (m).

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

A formula of logic is said to be valid if it is true under every interpretation (also called structure or model). See also model theory or mathematical logic#technical reference.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

The relation between the two notions is expressed by the deduction theorem and the resolution theorem.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

A tautology, or tautologous formula, is truth functionally valid. Not all valid formulas of quantificational logic are tautologies. See also the truth table article.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Logic: Logic (from Classical Greek λόγος (logos), originally meaning the word, or what is spoken, but coming to mean thought or reason) is most often said to be the study of arguments, although the exact definition of logic is a matter of controversy amongst philosophers (see below...

Social sciences: The social sciences are a group of academic disciplines that study the human aspects of the world. They diverge from the arts and humanities in that the social sciences emphasize the use of the scientific method and rigorous standards of evidence in the study of humanity, including quantitative and ...

Validity (psychometric): REDIRECT Validity (statistics)...