. An inference or an argument is valid if its conclusion follows deductively from its premises. The premises may be false, but if they are true the conclusion must be true. An inference is invalid if it is not valid. It is contravalid if an inference...

An intelligence test or examination rarely measures exactly what it is intended to measure. For example, a test of creativity might give results that are superficially plausible but which, on further investigation, turn out to be no more than a test of...

An expression of the capability of a scientific study to be able to identify or ascertain that which is being sought. This will depend primarily on the design of the study, the SENSITIVITY and SPECIFICITY of ascertainment techniques, and the conduct of...

The extent to which a test or other instrument measures what it is intended to...

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)....

TiVo Inc. on Thursday proclaimed itself winner of the latest round in its battle against EchoStar Communications Corp. after federal regulators validated the digital video recorder maker's patent that is central to the case.EchoStar was disappointed in the U.S. Patent and Trademark Office decision but...

A court has postponed the validation of parliamentary election results, officials said Wednesday, threatening to delay the formation of a government in Ukraine, which is struggling to emerge from prolonged political turmoil.The move came as President Viktor Yushchenko endorsed a parliamentary coalition made up of...

A court validated the results of parliamentary elections Thursday, opening the way for the formation of a government in this ex-Soviet republic struggling to emerge from prolonged political turmoil.The move was likely to be welcomed by the two pro-Western Orange Revolution parties led by President...