Found on web: Commoncog

Published on September 17, 2025

Commoncog by Cedric Chin is probably the most influential resource I’ve discovered on the Internet in the last couple of years. It’s deep. It’s grounded. It’s deliberate. It’s insightful. It’s judicious. It’s nuanced. It’s well written. It’s practical. If I were stranded on a desert island and could only receive updates from five websites, Commoncog would be one of them. It’s that good.

Consider the series on putting mental models to practice. There’s a very compelling argument for limits of scientific knowledge from practical point of view in part two; and right away other types of knowledge are proposed to fill the gap. Some of them are collectively called Naturalistic Decision Making models, elaborated on in part four. Part five is a real treasure - it provides detailed, actionable advice on developing proficiency in expertise-driven decision making. The whole series gives both theoretical framework and practical guidance with a proven track record.

These themes are then echoed in The Secret at the Heart of Continuous Improvement, which covers Plan-Do-Study-Act model - something that you might have heard about before. Nonetheless, Cedric manages to really nail down the importance of how the stages support one another, and the entire model as a whole. He then delivers a knockout punch with revolutionary framing - PDSA provides a methodology for single subject studies. It’s the ultimate tool for finding and refining what works for you.

There’s also entire series on Cognitive Flexibility Theory, which tries to uncover how people are learning in ill-structured domains - and provides tools to accelerate that learning. One of them is case library, which is explained in depth in How Note Taking Can Help You Become an Expert. It acknowledges the messiness of the real world and builds on the insight that experts are pattern-matching novel situations against all the cases they experienced or heard of, identifying similarities and differences. Becoming an expert is largely about growing this body of cases you can reference.

I’m truly captivated by these ideas. Where I stand right now, I believe that one of the most beneficial learning resources for testers is building a shared case library. I’ve been modestly contributing to that in this very blog. If this is something you would be interested in and would like to work on together, just send me a message.

Meanwhile, be sure to check out existing Commoncog article base and subscribe to their newsletter or RSS feed.