Reliability vs validity / & responsiveness

Standard error of measurement

amount of inconsistency or unreliability in the scores obtained on an instrument

test-retest reliability

Measure of test scores stability when using the same version of an instrument over 2 testing occasions under the same conditions

Parallel forms

Stability between scores obtained on two versions of the same instrument

Intrarater reliability

Stability of scores on a instrument when using the same rater across repeated measurements

Interrater reliability

stability of scores on an instrument when using different raters

Internal consistency

Degree of agreement between items in a measure that measure a single or unidimensional construct

Face related evidence (validity)

The appearance of test items in relationship to the purpose of the test

Content related evidence (validity)

The extent to which the test items represent the construct being measured

Criterion related evidence of validity

Relationship of the scores on an instrument to an external criterion (standards)

Concurrent validity

Correlation of the scores on a measure with those on existing measure, typically the gold standard use to measure the construct

Predictive validity

Ability of scores on the measure to predict future abilities or outcomes

Construct related evidence of validity

Relationship between the underlying theory of the construct and the scores on an instrument

Convergent validity

Correlation of scores on an instrument with certain other measures that may be similar to the construct or closely associated with the construct

Divergent validity

scores on the instrument diverge from those of other measures with a different construct and demonstrate a low correlation

Know-groups validity

Ability of a measure to differentiate between distinct groups of people such as those with and without the condition or with high and low levels of the trait

Factors

different aspects of a construct that are distinct enough to be identified through factor analysis methods; a single measure may have many

Floor effect

when the scores on a measure are not able to detect a change at the lower level of ability

Ceiling effects

observed when the scores are not able to detect change in the higher ability level

Sensitivity

ability of test scores to correctly detect a condition or impairment with high accuracy

Specificity

ability of the test scores to correctly reject those people who do not have the condition or impairment