Data Science Fundamentals

Probability sampling is defined as a sampling method in which every unit or entity in the population has a known and equal (or calculable) probability of being selected for the sample. This is typically achieved through random selection techniques such as simple random sampling, systematic sampling, or stratified sampling. In contrast, non-probability sampling relies on subjective judgment or convenience, so selection probabilities are unknown and not equal across the population, making it unsuitable when equal chance of selection is a requirement.