SI chpt 6

the extent to which an instrument measures what it is intended to measure

an instrument appears to test what it is supposed to and that it is a plausible method for doing so

indicates that the items that make up an instrument adequately sample the universe of content that defines the variable being measured. Most useful with questionnaires and inventories.

indicates that the outcomes of one instrument, the target test, can be used as a substitute measure for an established reference standard criterion test. Can be tested as concurrent or predictive validity

establishes validity when two measures are taken relatively the same time. Most often used when the target test is considered more efficient than the gold standard and, therefore, can be used instead of the gold standard.

establishes that the outcome of the target test can be used to predict a future criterion score or outcome

establishes the ability of an instrument to measure an abstract construct and the degree to which the instrument reflects the theoretical components of the construct

a measurement that defines the true value of a variable. In criterion-related validity, an instrument that is considered a valid measure and that can be used as the standard for assessing the validity of other instruments

a value used as a standard against which to judge a criterion; may or may not be a gold standard. Used to judge criterion-related validity or diagnostic accuracy.

two measures believed to reflect the same underlying phenomenon will yield similar results or will correlate highly

an approach in construct validation assessing the degree to which an instrument yields different results when measuring two different constructs; that is, the ability to discriminate between the constructs.

a trait cannot be assessed independently of some method

an exploratory multivariate statistical technique used to examine the structure within a large set of variables and to determine the underlying dimensions that exist within that set of variables.

(difference score); the difference between the outcome and the initial score.

a measurement limitation of an instrument whereby the scale cannot determine decreased performance beyond a certain level

a measurement limitation of an instrument whereby the scale cannot determine increased performance beyond a certain level

ability to detect minimal change over time; the ability of a test to demonstrate change

the smallest difference in a measured variable that signifies an important rather than trivial difference in the patient's condition. The smallest difference a patient or clinician would perceive as beneficial, and that would result in a change in the management of the patient. Also called minimal clinically important change (MCIC) or minimally important change (MIC)

interpretation of a score based on its actual value

interpretation of a score based on its value relative to a standard or "normal" score

accomplished by trying out a previously developed test on a new group with characteristics as close as possibile to those of the original