השוואת שיטות

	ניתוח עוצמה עבור מבחן t	ניתוח עוצמה רגרסיה מרובה
תחום	סטטיסטיקה	סטטיסטיקה
משפחה	Hypothesis test	Hypothesis test
שנת המקור	1969	1988
הוגה השיטה	Jacob Cohen	Jacob Cohen
סוג	Sample size determination	A priori sample size determination
מקור מכונן	Cohen, J. (1988). Statistical Power Analysis for the Behavioral Sciences (2nd ed.). Lawrence Erlbaum Associates. ISBN: 978-0805802832	Cohen, J. (1988). Statistical Power Analysis for the Behavioral Sciences (2nd ed.). Lawrence Erlbaum Associates. ISBN: 978-0805802832
כינויים	t-test power analysis, sample size calculation for t-test, Güç Analizi — t-Testi	regression power analysis, sample size estimation regression, f² power analysis, Güç Analizi — Regresyon
קשורות	5	4
תקציר	Power analysis for the t-test is a sample size planning procedure that determines how many participants are required to detect a mean difference of a given magnitude with acceptable probability. Formalised by Jacob Cohen in his 1969 and 1988 editions of Statistical Power Analysis for the Behavioral Sciences, it links four quantities — effect size (Cohen's d), significance level (α), statistical power (1 − β), and sample size — so that fixing any three allows calculation of the fourth.	Power analysis for multiple regression is a pre-study procedure, formalised by Jacob Cohen (1988), that calculates the minimum sample size needed to detect a regression effect of a given size with adequate statistical power. It uses the anticipated R² (or the equivalent Cohen's f² effect size) and the number of predictors to determine how many observations must be collected before data collection begins.