Understanding how to evaluate surgical interventions is crucial for patient care. The objective of this chapter is to highlight key methodological concepts that are essential for those reading surgical literature. We will discuss specific issues including randomization, blinding, sample size, and power calculations. Common statistical concepts including odds, odds ratios, risk, risk ratios, relative risk reduction, absolute risk reduction, and number-needed-to-treat, as well as multivariable analysis are explained for the reader. We highlight these concepts through the critical appraisal of a scientific paper.