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CHAPTER 20 : VALIDITY AND RELIABILITY - Coggle Diagram
CHAPTER 20 : VALIDITY AND RELIABILITY
Introduction
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 consistency across time (test-retest reliability), across items (internal consistency), and across researchers (interater reliability)
Validity is the extent to which the scores actually represent the variable they are intended to. Validity is a judgment based on various types of evidence.
Validity
in the others words, " the degree to which you're measuring what you claim to measure"
2 broad types of validity
internal validity
to the degree of confidence that the causal relationship being tested is trustworthy and not influenced by other factors or variables
external validity
to the extent to which results from a study can be applied (generalized) to other situations, groups or events
refers to the accuracy of an instrument/measurement
Qualitative
reliability- minor role, perhaps the extent to which multiple coders agree on codes
validity- extent that the information is accurate and useful (many perspectives and names)
Reliability
necessary but not sufficient in determining validity
2 common types of reliability
Inter-Rater : Kappa statistic
internal consistency: Cronbach's alpha
thought of an individual's "true score" in the phenomenon you aim to measure minus " measurement error"
refers to consistency of an instrument/measurement
Quantitative
validity- extent to which one can draw meaningful inferences
discuss validity, reliability of the instruments you use in the methods section (from past uses) and in results (from current study)
reliability- extent to which the score are consistent & stable
reduce threats to internal validity(extent to which cause and effect claims can be made) and external validity (extent to which the results can be generalized to others person, settings or times)
conclusion
validity is important bcs if an an instrument does not accurately measure what is supposed ti, there is no reason to use it even if it measures.
reliability is important to measure the consistency of your measurement , or the degree to which an instrument measures the same way each time it is used under the same conditions with the same subjects