Assessing Data Quality

• Reliability, one of two primary criteria for assessing a quantitative instrument, is the degree of consistency or accuracy with which an instrument measures an attribute.
• Validity is the degree to which an instrument measures what it is supposed to be measuring.
• Sensitivity is the instrument’s ability to identify a case correctly (i.e., its rate of yielding true positives).
• Specificity is the instrument’s ability to identify noncases correctly (i.e., its rate of yielding true negatives).
• Credibility refers to the believability of the data.
• Triangulation is the process of using multiple referents to draw conclusions about what consti tutes the truth.