validity

n. state of being valid, legitimacy; soundness, condition of being well-founded

The term validity as it occurs in logic refers generally to a property of deductive arguments, although many logic texts apply the term to statements as well (a statement is a sentence that “has a truth value,” i.e., that is either true or false). For the purposes of this article, an argument is a set of statements, one of which is the conclusion and the rest of which are premises. The premises are reasons intended to show that the conclusion is, or is probably, true.
See more at Wikipedia.org...

Noun
1. the quality of being logically valid
(synonym) cogency, rigor, rigour
(hypernym) credibility, credibleness, believability
2. the quality of having legal force or effectiveness
(synonym) validness
(hypernym) legality
(hyponym) effect, force

(n.)
Value.
  

(n.)
The quality or state of being valid; strength; force; especially, power to convince; justness; soundness; as, the validity of an argument or proof; the validity of an objection.
  

(n.)
Legal strength, force, or authority; that quality of a thing which renders it supportable in law, or equity; as, the validity of a will; the validity of a contract, claim, or title.
  

in marketing research, the obtaining of the right information for the purposes of the study.