So sánh phương pháp

	Sức mạnh thống kê và Kích thước mẫu	Effect Size
Lĩnh vực	Thống kê nghiên cứu	Thống kê nghiên cứu
Họ	Process / pipeline	Process / pipeline
Năm ra đời	1988	1988
Người khởi xướng	Jacob Cohen	Jacob Cohen
Loại	Concept	Concept
Công trình gốc	Cohen, J. (1988). Statistical Power Analysis for the Behavioral Sciences (2nd ed.). Lawrence Erlbaum Associates. ISBN: 0-8058-0283-5	Cohen, J. (1988). Statistical Power Analysis for the Behavioral Sciences (2nd ed.). Lawrence Erlbaum Associates. ISBN: 0-8058-0283-5
Tên gọi khác	power analysis, sample size calculation, 1 minus beta, sensitivity	ES, Cohen's d, standardized effect, practical significance
Liên quan	4	4
Tóm tắt	Statistical power is the probability of detecting a true effect if it exists (1 − β). Power analysis determines the sample size required to detect a hypothesized effect size with specified Type I error (α) and Type II error (β) rates. Introduced by Jacob Cohen (1988), power analysis is foundational to research design: underpowered studies produce inflated effect size estimates and are unlikely to replicate. The standard benchmark is 80% power (β = 0.20), though critical studies may require 90% power.	Effect size quantifies the magnitude of a research finding independent of sample size. While a p-value tells you whether a result is statistically significant, an effect size tells you how big the result is. Jacob Cohen formalized effect size measurement in behavioral sciences (1988), establishing standard benchmarks (small = 0.2, medium = 0.5, large = 0.8 for Cohen's d). Effect sizes are essential for meta-analysis, power analysis, and communicating the practical importance of research findings.