Biostatistics Series – 2: Descriptive Statistics

Abstract

This editorial provides a comprehensive overview of descriptive statistics, focusing on how to effectively summarize quantitative variables. It details the primary measures of central tendency—mean, median, and mode—and emphasizes that choosing the correct measure depends heavily on data normality and the presence of skewness. Because central tendency alone provides an incomplete picture, the text also explores essential measures of dispersion, including standard deviation, variance, range, and interquartile range (IQR). It outlines practical methods for evaluating data distribution, testing for normality using non‐parametric tests, and detecting outliers via Tukey’s fences and Box‐and‐Whisker plots. Additionally, the document defines the fundamental scales of measurement (nominal, ordinal, interval, and ratio), alongside specialized scoring systems like the Likert scale for evaluating knowledge, attitude, and practice. Finally, it summarizes the key mathematical properties, strengths, and limitations of these statistical measures.