Lesson One
Lesson
Introduction Where do data come from? You will look at 3 major schemes of collecting data in this module: Sample Surveys Observational Studies Experiments We will also review the role of randomization in these three types of studies. Although there are other ways to collect data, the first three are particularly good examples because they will help you understand what you can conclude from data—and what you can’t. In this lesson, you will: Study sample survey data Understand what is a sample of a population Learn unbiased methods of choosing a sample Investigate convenience samples as an example of a bias Learn different ways by which bias can be introduced in the data