Statistics You Can See, Touch, and Understand
A friendly statistics course where you learn each idea by playing with it: drag, poke and watch what happens, with no wall of formulas first. Try it right now:
8 courses · 105 interactive lessons · free forever, no sign-up
Eight courses in two tracks: the Statistics Core teaches the analysis, the Research Toolkit covers everything around it. Click any topic to open its interactive lesson.
The Statistics Toolbox
Choosers, calculators, cheat sheets, datasets, flashcards, guides and the quiz, all made to use alongside the lessons. They are free, run in your browser and need no sign-up.
About the instructor
Hi, I'm Dr. Hakan Karsilar, a scientist and lecturer at University College Groningen, University of Groningen. I built this site because I believe statistics doesn't have to be intimidating. With the right visualizations and a bit of hands-on practice, anyone can build real intuition for how data works.
Every section is designed from the ground up: no hand-waving, no "just trust the formula." You'll see each concept in action, follow worked examples, and test yourself along the way. If you're curious about the research behind the teaching, my publications are on Google Scholar.
Everything here is openly licensed: the lessons, problems and datasets under CC BY 4.0, the code under MIT. Teach from it, translate it, remix it into your own materials, or fork the whole thing. The license page has the details and the credit line.
Accessibility
StatsCapybara aims to meet WCAG 2.1 AA. Every page works with a keyboard: there's a skip link, visible focus rings, and a focus-trapped search. Page text meets 4.5:1 contrast in both light and dark themes, and links in the text are underlined, so you can tell them apart without seeing color. Form controls and charts are labeled for screen readers, and live readouts are announced as you move a slider. The site follows your system's reduce motion setting, and its dark mode until you pick a theme yourself.
The interactive visualizations are canvas graphics, so they depend on sight, but each one has text readouts beside the picture, and its controls (sliders, buttons, and arrow keys on the ones you drag) work without a mouse. Labels drawn inside a chart use the chart's own colors, and some of those are lighter than the page text. If something is hard to use with a keyboard or screen reader, please tell me. Work on accessibility is ongoing.
📴 Works offline once visited. Open a lesson on wifi and you can still read it on the train without a signal. You can also add StatsCapybara to your home screen.