Lesson 1 — Introduction

Why Data Science?

How a golden retriever named Rhonda teaches us everything we need to know about statistics.

Meet Rhonda 🐕

Rhonda is a golden retriever — the first dog you've ever seen. She's friendly, loves tennis balls, and is 30 inches tall.

"Is Rhonda taller than other golden retrievers? You might have a gut feeling... but how do you provide evidence?"

The core problem

Can you compare Rhonda to every golden retriever in the world? Past, present, and future?

No — and that's exactly why we need statistics.

Statistics lets us draw conclusions from a sample without measuring the entire world.

Sample size matters

1

Compare Rhonda to 1 dog
Not convincing at all

5

Compare to 5 dogs
A little more confident

30

Compare to 30 dogs
Now we can draw real conclusions!

More data = more confidence in our conclusions.

What statistics can do

🔍 Detect patterns and differences in data
🔗 Find relationships between variables (e.g. diet & height)
🌍 Apply to medicine, genetics, behavior, plants, and more

Statistics is about using data to make conclusions — not just gut feelings.

Real-world application

Wisconsin Fast Plants 🌱

Throughout this course, we'll apply statistics to real plant data — height, germination time, leaf number — to build hands-on intuition for every concept.

fastplants.org