Learn the distinctions between simple and stratified random sampling. Understand how researchers use these methods to accurately represent data populations.

Computers are known to be precise and — usually — repeatable. That’s why it is so hard to get something that seems random out of them. Yet random things are great for games, encryption, and multimedia ...

These are not the kinds of objects that concern Scott Sheffield. Sheffield, a professor of mathematics at the Massachusetts Institute of Technology, studies shapes that are constructed by random ...