Educational Psychology / Unit 12 EDP 1110 short lesson, about 20 seconds
Estimating Reliability
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The idea
Reliability is estimated with coefficients: test-retest, giving the same form twice; alternate-form, giving two equivalent forms; and internal consistency, from one administration, by split halves, Kuder-Richardson formula 20 or coefficient alpha; scorer consistency covers raters.
In practice
Comparing scores on the odd and even items of one test is a split-half estimate.
Where people slip
Each coefficient captures a different source of error.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
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