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circadian rhythm

any periodic variation in physiological or behavioral activity that repeats at approximately 24-hour intervals, such as the sleep–wake cycle. Also called diurnal rhythm. Compare infradian rhythm; ultradian rhythm. See also biological rhythm.

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Psychology term of the day

November 22nd 2024

population variance

population variance

(symbol: σ2) the square of the population standard deviation. It is a measure reflecting the spread (dispersion) of scores in a complete population of interest (e.g., the test scores of all students at a school).