Think Clearly: Eight Simple Rules to Succeed in the Data Age
Think Clearly brings together the ideas that will help you analyze anything.
The book is in its fifth edition and has already been published in English and Korean. In 2026 there will be editions in German, Chinese, Czech and Japanese.
Get your copy of Think Clearly
“This eye-opening book challenges us to think critically. A must-read for anyone who wants to better understand the world.”
“Kiko Llaneras is one of the most consistently interesting data journalists to have emerged in the last decade”
The eight rules you'll learn from the book
- Accept How Complex the World Is
- Think in Numbers
- Protect your Samples from Biases
- Accept that Causation is Challenging
- Don't Underestimate the Power of Randomness
- Predict Without Ignoring Uncertainty
- Accept the Trade-offs
- Don’t Trust Your Intuition
Within each section, there are plenty of ideas, ranging from tips (do back-of-the-envelope calculations) to warnings (don’t confuse noise with signal).
Reviews of Think Clearly
“Kiko Llaneras is one of the most consistently interesting data journalists to have emerged in the last decade.”
“If you want to get better at interpreting and explaining data, I’d recommend Think Clearly by Kiko Llaneras. It’s full of great data journalism insights and examples.”
“The author interprets the world with numbers and organizes all complex phenomena into a concise structure... The feeling that my complex mind is being organized in real-time is very, very good.”
“Think Clearly is an invaluable resource for anyone seeking to enhance their critical thinking skills in an increasingly data-driven world.”
“Kiko Llaneras has established himself as the leading voice in Spanish data journalism thanks to his keen eye for extracting meaning from data and presenting it to the public.”
“A must have for the data age. This book is for anyone interested in data, whether that's working as an analyst or just wanting to understand more. It's super accessible, talking to real life scenarios and demystifying complex uses of data into easy relatable chapters.”
“It's a very quick read, written in an engaging style with lots of examples […] It is divided into eight rules and proposes many practical cases. Highly recommended.”
“This insightful book challenges us to think more critically and empowers us to make better decisions for a brighter future. A must-read for anyone who wants to understand the world better.”
“Kiko is one of the clearest data communicators I know. In this brilliant book, he empowers you to do the same.”
“An addictive read.”
“Thoroughly informative and engaging [...] I am going straight back for a re-read.”
“A refreshingly positive take on number and measurement. The trick to thinking with data is to stop taking the stuff on trust, and start learning how to use it. Practical tools and shortcuts make this a compelling, intellectual self-help book.”
“I can say he had me immediately when I saw Rule One 'Accept How Complex the World Is'. Bravo Kiko!”
“The book is easy to read. It's accessible to a wide audience. It's entertaining while being educational. It contains numerous real-world examples to illustrate concepts and is full of interesting anecdotes and fascinating details.”
“Common sense to navigate the data jungle.”
“Choose doubt over certainty, complexity over simplicity, and caution over speed. In this way, we might become a bit more rational, yet paradoxically, a bit more human. This is the warm message Llaneras wants to convey through the cold language of numbers and data.”
“There's something that Kiko has managed to evoke in me with this book, and it's that intellectual satisfaction you get when something complex and important turns out to be interesting and clear. Highly recommended.”
The back cover
“Think Clearly” is an essential guide to decoding the complexities of today's world. It will transform how you see and use data in every aspect of your life.
It’s almost impossible to feel confident we’ve made the right choice when we are constantly faced with conflicting data. From choosing the right school for our children to understanding major social and political events, making informed decisions can feel overwhelming. In a world overflowing with data, it is more important than ever to decipher what the numbers tell us.
Drawing on years of work interpreting and explaining data about everything, renowned data journalist Kiko Llaneras offers practical tools and shortcuts to help us understand numbers and make better decisions with a quantitative mindset.
Through fascinating examples, he reveals the surprising insights that a data-driven perspective can offer:
- What caused the Chernobyl disaster
- How Barack Obama made decisions and slept so peacefully during his presidency
- What are the secrets of superforecasters
- Why so many footballers are born in January

References and recommended reading
I've gathered on a separate page the readings, sources and articles that go with each part of the book, in case you want to dig deeper or check a figure.
See references