validity and reliability of measurement instruments used in research

The tool which is already demonstrated to be valid is the “gold standard” with which the other measure must correlate.ġ0 Predictive validity The ability of one measure to predict another future measure of the same concept. Ways of arriving at construct validity Hypothesis testing method Convergent and divergent Multitrait-multimatrix method Contrasted groups approach factor analysis approachĩ Concurrent validity Correspondence of one measure of a phenomenon with another of the same construct.(administered at the same time) Two tools are used to measure the same concept and then a correlational analysis is performed. Can an instrument to measure anxiety pick up different levels of anxiety or just its presence or absence? Measure two groups known to differ on the construct. 80 or more is desirable.Ĩ Construct validity Sensitivity of the instrument to pick up minor variations in the concept being measured. Usually evaluated and scored by experts in the content area.

Entire range or universe of the construct is measured. Question-is there any time when face validity is not desirable?ħ Content validity Content of the measure is justified by other evidence, e.g. Face validity is sometimes considered a subtype of content validity. Concept=pain level Measure=verbal rating scale “rate your pain from 1 to 10”. “intuitive, arrived at through inspection” e.g. face content construct concurrent predictive criterion-relatedĦ Face validity Just on its face the instrument appears to be a good measure of the concept. Observed Score=true score + error variance (actual score obtained) (stable score) (chance/random error) (systematic error)ģ Validity The accuracy of the measure in reflecting the concept it is supposed to measure.Ĥ Reliability Stability and consistency of the measuring instrument.Ī measure can be reliable without being valid, but it cannot be valid without being reliable.ĥ Validity The extent to which, and how well, a measure measures a concept. 1 Reliability and Validity of Research InstrumentsĪn overview Reliability and Validity of Research InstrumentsĢ Measurement error Error variance-the extent of variability in test scores that is attributable to error rather than a true measure of behavior.

Validity and reliability of measurement instruments used in research