ppt Establishing the Validity and Reliability of a Research Instrument.pptx

ppt Establishing the Validity and Reliability of a Research Instrument

1. Establishing the Validity and Reliability of a R esearch Instrument JENNELYN S. MALTIZO Discussant

2. What is validity ? Validity is about the accuracy of a measure.

3. What is reliability ? Reliability is about the consistency of a measure.

4. Types of Validity

5. 1 . Construct Validity t he adherence of a measure to existing theory and knowledge of the concept being measured.

6. 2. Content Validity - t he extent to which the measurement covers all aspects of the concept being measured.

7. 3. Criterion Validity - t he extent to which the result of a measure corresponds to other valid measures of the same concept.

8. The Concept of Reliability

9. 1. Test-Retest Reliability - t he consistency of a measure across time.

10. 2. Inter-Rater Reliability - t he consistency of a measure across raters or observers.

11. 3. Internal Consistency Reliability - t he consistency of the measurement itself.

12. 4. Parallel Forms Reliability - it is a measure of reliability used in psychometrics to assess the consistency of test scores across different versions, or forms, of a test that are designed to measure the same construct.

13. 5. Split-half Reliability - it is a measure of internal consistency reliability used in psychometrics to assess the reliability of a test.

14. Threats to Validity

15. 1. Selection Bias - occurs when participants selected for the study are not representative of the population being studied.

16. 2. Maturation - r efers to changes in participants over time that affect the outcome of the study, independent of the treatment or intervention.

17. 3. History - e xternal events or experiences that occur during the study and affect participants’ responses, confounding the results.

18. 4. Testing Effects - o ccur when participants’ responses are influenced by having taken the test previously.

19. 5. Instrumentation - c hanges in the measurement instrument or procedures over the course of the study that affect the results.

20. 6. Regression Toward the Mean - r efers to the tendency for extreme scores on a variable to move closer to the mean upon retesting.

21. 7. Experimental Mortality - occurs when participants drop out of the study before it is completed, potentially biasing the results.

22. Threats to Reliability

23. 1. Measurement Error - r andom errors or inconsistencies in measurement that can occur due to various factors such as human error, instrument malfunction, or ambiguous wording of items.

24. 2. Inter-Rater Variability - d ifferences in ratings or judgments between different observers or raters.

25. 3. Test-Retest Variability - c hanges in participants’ responses upon retesting, which may not reflect true changes in the construct being measured.

26. 4. Sampling Variability - v ariability in results due to difference in the composition of samples or participants across different administrations of the test.

27. 5. Order Effects - o ccur when the order in which items are presented influences participants’ responses.

28. 6. Response Bias - s ystematic tendencies for participants to respond in a certain way, regardless of the content of the items.

29. 7. Instrumentation Changes - c hanges in the measurement instrument or procedures over time that affect the consistency of measurement.

30. Thank You for Listening!