Reliability and Validity

Internal consistency

Internal consistency

________: used to assess how well the different items measure the same characteristic by separating the items within a group and comparing the data with the idea that both scores will be the same.

Reliability

________: how consistently or dependently does a measurement scale measure what it is supposed to be measuring.

key concepts

In the study of personality, or more broadly, individual differences, two ________ within this area of psychometrics are reliability and validity.

Validity

________: whether or not it is reliably measuring what you want it to measure.

Concurrent validity

________: assesses the extent to which a measurement scale under development correlates with the "gold standard "by testing the developing scale with one that is either currently used or already created.

Convergent Validity

________: assesses the sensitivity of the scale, testing the hypothesis of how the scale will correlate to the measure.

Divergent Validity

________: assesses the specificity of the scale, testing the variance in results the scale gives in terms of the measure tested.

Note 1

The main purpose of this reading is to learn key concepts in psychometrics (i.e., metrics, or measurement, of psychological constructs)

Note 2

The authors describe a type of validity called discriminant validity

Reliability

how consistently or dependently does a measurement scale measure what it is supposed to be measuring

Test-retest reliability

a commonly used indicator of the reliability of a measurement scale where the measurement scale under development is administered on two different occasions to the same sample and the scores are compared

Internal consistency

used to assess how well the different items measure the same characteristic by separating the items within a group and comparing the data with the idea that both scores will be the same

Validity

whether or not it is reliably measuring what you want it to measure

Face validity

assessment of whether a measurement scale looks reasonable, are the items included in the scale relevant, questioned by experts/researchers

Content validity

measures whether a scale has included all the relevant and excluded irrelevant issues in terms of its content, assessed by an expert panel/compared literature/both

Concurrent validity

assesses the extent to which a measurement scale under development correlates with the "gold standard" by testing the developing scale with one that is either currently used or already created

Predictive validity

correlates the results of one scale with the results of a second scale that is administered later to measure how well the item or scale predicts expected future observations

Construct validity

when there is not a gold standard/current measure, testing to what extent the measurement scale under development correlates with the construct under investigation by defining the topic and stating/disproving a hypothesis

Convergent Validity

assesses the sensitivity of the scale, testing the hypothesis of how the scale will correlate to the measure

Divergent Validity

assesses the specificity of the scale, testing the variance in results the scale gives in terms of the measure tested

If a personality measure is reliable, does that mean it is valid too?

Yes, because if it is a reliable measure, the result will be consistent and therefore a valid measure of the result

What about if a measure is valid, does that mean it must be reliable?

No, because a measure could be valid for a certain circumstance but not applicable in other situations and therefore not a reliable measure for a specific result.