RESEARCH METHODOLOGY - REALIABILITY vs VALIDITY
- 1. REALIABILITY AND VALIDITY A.JEEVARATHINAM Assistant Professor Department of Home Science V.V.Vanniaperumal College for Women Virudhunagar
- 2. Reliability vs Validity • Reliability and validity are concepts used to evaluate the quality of research. • They indicate how well a method technique. or test measures something. • Reliability is about the consistency of a measure, and validity is about the accuracy of a measure.
- 3. Reliability- Definition • Reliability in research is the measure of the stability or accuracy of the methods and results of an analysis. • It means obtaining identical results after repeating the same procedures several times. • When a measurement is consistent it’s reliable. • If the outcome of the research from one source produces equivalent information in other sources, users' trust in the information increases. • A correlation coefficient can be used to assess the degree of reliability. • If a test is reliable, it should show a high positive correlation.
- 4. Reliability- Example • For example, if you scored 95% on a test the first time and the next you score, 96%, your results are reliable. • So, even if there is a minor difference in the outcomes, as long as it is within the error margin, your results are reliable. • Imagine testing the effectiveness of a new study drug by measuring participants' blood pressure before and after taking the medication. • If multiple trials with different groups of participants show similar results, the measurement method is considered reliable.
- 5. Validity - Definition • Validity refers to whether a test measures what it aims to measure. • A measurement or test is valid when it correlates with the expected result. • It examines the accuracy of your result. • If research has high validity, that means it produces results that correspond to real properties, characteristics, and variations in the physical or social world. • High reliability is one indicator that a measurement is valid. • If a method is not reliable, it probably isn’t valid. • Validity is harder to assess than reliability, but it is even more important.
- 6. Validity - Example Example If a symptom questionnaire results in a reliable diagnosis when answered at different times and with different doctors, this indicates that it has high validity as a measurement of the medical condition. The thermometer that you used to test the sample gives reliable results. However, the thermometer has not been calibrated properly, so the result is 2 degrees lower than the true value. Therefore, the measurement is not valid. A driving test a valid driving test should include a practical driving component and not just a theoretical test of the rules of driving. A valid language test for university entry, for example, should include tasks that are representative of at least some aspects of what actually happens in university settings, such as listening to lectures, giving presentations, engaging in tutorials, writing essays, and reading texts. It’s like ensuring that the puzzle pieces you’re putting together actually form the intended picture.
- 7. THANK YOU