R for Probability and Statistics

Probability Sampling with R

Understanding Sampling Methods

Image by Riho Kroll available at Unsplash

What is Sampling?

Sampling is the process of selecting a random number of units from a known population. It allows obtaining information and drawing conclusions about a population based on the statistics of such units (i.e. the sample), without the need of having to study the entire population.

Why is Sampling Used?

Sampling is performed for multiple reasons, including:

• Cases where it is impossible to study the entire population due to its size
• Cases where the sampling process involves samples destructive testing
• Cases where there are time and costs constrains

Sampling Techniques

There are two types of sampling techniques:

• Probability sampling: cases when every unit from a given population has the same probability of being selected. This technique includes simple random sampling, systematic sampling, cluster sampling and stratified random sampling.
• Non-probability sampling: cases when units from a given population do not have the same probability of being selected. This…