Slides for ‘Elements of Sampling Survey’

Author

Longhai Li

Published

September 21, 2026

Table of Content

Nested ellipses labelled target population, sampling frame and sample1. Introduction to Sampling Surveys Sampling distribution of the sample mean: bell curves centred at the population mean that narrow as the sample size grows2. General Probability Sampling Grid of 70 dots with 12 chosen at random highlighted in red3. Simple Random Sampling
Grid of dots split into three shaded strata with 4 dots highlighted in each4. Stratified Sampling Scatter plot of y against x with a ratio line through the origin and a dashed regression line5. Ratio and Regression Estimation Dots grouped into 15 boxes (clusters) with 3 whole clusters highlighted in red6. Cluster Sampling
Grid of dots of different sizes with 12 highlighted, mostly the larger ones7. Unequal Probability Sampling

Image credits: (2) Sampling distribution, Biggerj1, CC BY 4.0, from Wikimedia Commons; (1) and (3)–(7) generated in R for this page.