This document discusses key concepts in sampling design, including: 1. It defines key terms like population, sample, sampling frame, sampling error, and non-sampling error. 2. It outlines the steps in developing a sampling plan, including defining the population, choosing a data collection method, identifying the sampling frame, selecting a sampling method, determining sample size, and developing operational procedures. 3. It describes different sampling methods like probability and non-probability sampling, and provides examples of methods like simple random sampling, systematic sampling, and stratified sampling under probability sampling.