What is knowledge depth?

Example: You have 40 notes about distributed systems. When you map the links between them, you find that almost every note connects to multiple others — consensus algorithms link to failure modes, which link to CAP theorem, which links to partition tolerance, which links back to consensus. The region is thick with edges. Then you look at your 40 notes about nutrition. Most sit in isolation — a few link to 'meal planning,' but the connections stop there. You don't need a quiz to know which subject you understand deeply and which you've merely collected facts about. The graph already told you.

This concept is part of Knowledge Graphs in the How to Think curriculum.