השוואת שיטות

	ניתוח עוצמה	ניתוח גודל אפקט
תחום	סטטיסטיקה	סטטיסטיקה
משפחה	Hypothesis test	Hypothesis test
שנת המקור	1969 (1st ed.); 1988 (seminal 2nd ed.)	1969 (first edition); 1988 (definitive second edition)
הוגה השיטה	Jacob Cohen	Jacob Cohen
סוג	Sample size and power planning	Standardized magnitude estimation
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	sample size calculation, power calculation, sensitivity analysis, a priori power analysis	effect magnitude estimation, standardized effect measure, practical significance analysis, ES analysis
קשורות	5	4
תקציר	Power analysis is a planning and evaluation technique that quantifies the probability of detecting a real effect of a given magnitude at a chosen significance level. It links four quantities — sample size, effect size, significance level (alpha), and statistical power (1 minus beta) — so that researchers can determine the sample size needed before data collection or evaluate the sensitivity of a completed study.	Effect size analysis quantifies the practical magnitude of a statistical result independently of sample size. Rather than asking only whether a difference or relationship is statistically significant, it asks how large it is, using standardized indices such as Cohen's d, eta-squared, omega-squared, or Pearson's r that allow direct comparison across studies and populations.