Instrument Validity/Reliability

Face validity

• looks like it is measuring a particular characteristic

• relies on subjective judgment

• ensure cooperation of subjects—not always reliable

Content Validity

• extent to which measurement instrument is a representative sample of content being measured

• the items on the test represent the entire range of possible items the test should cover

  • considered when assessing achievement or knowledge gained

  • considered high when questions reflect various parts of content

Criterion Validity

• results of instrument correlate with another related measure

• personality test

• self report

• new measure of particular characteristic is highly related to a well established measure of the same characteristic

Construct Validity

• instrument measures characteristic that cannot be observed

• increase in anxiety in traumatized people

• prejudice, motivation, intelligence, creativity

Interrater reliability

2 or more evaluations give same judgment

Test-retest reliability

same instrument yields same results on same person more than once

equivalent forms reliability

2 versions of same instrument yield same results

internal consistency reliability

all items measured with a single instrument yield similar results