Chapter 10. Sampling Techniques and Population

Sampling links a target population to a manageable set of observations and strongly influences the interpretation and generalizability of research findings. This chapter introduces probability and non-probability sampling, comparing their selection principles, practical uses, strengths, and limitations. It explains how research aims, population characteristics, precision requirements, and study constraints inform the choice of sampling strategy. Particular attention is given to sample size determination, sample size formulas, sampling errors, selection bias, and implementation challenges. The discussion clarifies the implications of different approaches for statistical inference and for qualitative or exploratory investigations. The chapter provides a basis for designing defensible sampling plans and transparently reporting sampling decisions.