Lesson: Stratification

This lesson delves into the concept of stratification, a sampling technique utilized to divide a population into separate groups known as strata. The lesson explains the purpose of stratification and why it is essential to include elements from every important subgroup within a sample to reduce the variability of items in each stratum, lowering sampling risk. Examples are provided to illustrate the process of stratification in real-life scenarios, such as selecting a diverse sample of sales invoices or students from different states. The lesson emphasizes the benefits of stratification in increasing efficiency and reducing sample size while ensuring a representative selection of the entire population.