  In statistics education, the concept of population is widely felt hard to
grasp, as a result of vague explanations in textbooks. Some textbook authors
therefore chose not to mention it. This paper offers a new explanation by
proposing a new theoretical framework of population and sampling, which aims to
achieve high mathematical sensibleness. In the explanation, the term population
is given clear definition, and the relationship between simple random sampling
and iid random variables are examined mathematically.
