What does it mean that hierarchy refactoring?

When your hierarchy becomes awkward restructure it rather than forcing things to fit.

Example: You've organized your professional knowledge under 'Technical Skills' and 'People Skills.' But coaching engineers, running architecture reviews, and writing technical RFCs all straddle both categories. You keep jamming them under one or the other with mental footnotes. The hierarchy isn't wrong — it's outgrown. Split the axis: organize by activity type (building, reviewing, teaching, deciding) instead of by skill domain. The cross-cutting items now have natural homes, and you stop maintaining a mental exception list.

Try this: Open your primary knowledge system — notes app, vault, project folders, whatever you use. Find one category that has become a dumping ground: too many items, too many 'sort of fits here' entries, or subcategories that overlap. Write down three alternative ways you could split or restructure that single node. Pick the one that eliminates the most exceptions. Execute the restructure now — move the items, rename the folders, update the links. Time yourself. It will take less time than you expect.