The Importance of Sample Size Calculation and Power Analysis in Research Studies

Decisions about sample size and statistical power are often treated as a technical afterthought in research proposals, squeezed into a single sentence or delegated entirely to software. Yet these decisions sit at the intersection of scientific validity, feasibility, and ethics and directly determine whether a study can answer its primary question in a trustworthy way. Sample size calculation and power analysis should no longer be regarded as optional technicalities appended at the end of a protocol. They are central to scientific integrity, determining whether a study can credibly answer its research question, justify the burdens placed on participants, and make a meaningful contribution to the literature. In this editorial, we aim to draw attention to sample size calculation and power analysis, outlining their conceptual foundations, practical implementation, and ethical implications in contemporary research.