ELI5: Explain Like I'm 5

Sampling (information theory)

Sampling in information theory is about taking a small part of something to get a good understanding of the larger whole. Imagine you have a big jar of jellybeans - you want to know how many red jellybeans are in the jar, but it would take you forever to count all of them one by one. So you take a small handful of jellybeans, count how many are red, and use that information to make an estimate of how many red jellybeans are in the whole jar.

This idea of taking a small part to represent the larger whole can also be applied to information. Let's say you have a really long book with lots of words in it, but you only want to know about a specific topic in the book. Instead of reading the entire book, you could just read a few pages or paragraphs that are specifically about that topic. This is like taking a sample of the book to get the information you need, instead of reading the whole thing.

Sampling in information theory is all about making the most efficient use of your time and resources by focusing on a small part of something to understand and represent the larger whole. The key is to choose the right sample size and to make sure that the sample is representative of the whole picture.