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Kuder–Richardson formulas

two methods, Kuder–Richardson formula 20 (K-R 20) and Kuder–Richardson formula 21 (K-R 21), for assessing the internal consistency reliability of a test or subtest made up of dichotomous variables. The K-R 21 requires that all of the dichotomous variables be equally difficult, whereas the K-R 20 does not. For example, a teacher could use the K-R 21 formula to calculate internal consistency reliability for a test of 20 equally difficult items but would use the K-R 20 formula for test items differing in difficulty level. [Frederic Kuder (1903–2000) and Marion Webster Richardson (1896–1965), U.S. psychologists]

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Psychology term of the day

December 30th 2024

labial

labial

1. adj. of or relating to the lips.

2. adj. denoting a speech sound made with the lips, for example, [b], [p], [m], [w], [f], or [v]. If the sound is made with both lips, it is described as bilabial; if the sound is made with the lower lip and the upper teeth, it is termed labiodental.

3. n. a labial speech sound.