This section provides a high-yield review of biostatistics and clinical research design for the INBDE, focusing on how research is structured, analyzed, and interpreted in dentistry. It covers PICO and FINER for building and evaluating clinical questions, hypothesis testing, scientific manuscript structure, variables and data types, sampling and randomization, and systematic bias analysis including screening biases. Emphasis is placed on common board traps and applying statistical reasoning to evidence-based clinical decision-making.