What is regression?

Regression is when we try to figure out how one thing affects another using patterns and clues.

Imagine you're trying to guess how many jellybeans are in a jar. If you've seen similar jars before, you might think: The bigger the jar, the more jellybeans it has. So you use what you know about size and past jars to make your best guess. That's like regression, using clues from things we already know to predict something new.

Think of regression like learning a recipe by watching someone else cook. If you see that every time they add 2 cups of flour, the cake gets bigger, you can use that pattern to guess how big the cake will be if they add more flour next time. In this case:

• Flour amount is what we're using as our clue.
• Cake size is what we’re trying to predict.

Let's say your friend wants to know how long it’ll take to walk to school based on the distance. They notice that walking 1 block takes about 2 minutes. So, if they have to walk 5 blocks, they multiply: 5 blocks × 2 minutes = 10 minutes. That’s a simple kind of regression, finding a pattern and using it to predict something new.

Just like you use patterns in everyday life, scientists and mathematicians use regression to make smart guesses about things we can't always see right away!