Create explicit categories for organizing knowledge.
Every category you create determines what you group together and what you separate.
There is no single correct way to categorize — categories serve purposes.
When you name and define your categories you can evaluate and improve them.
Dividing things into only two groups forces a false simplicity.
Many things are better understood as positions on a continuum than as discrete categories.
Nested categories with parent-child relationships create powerful organizational structures.
The best category systems have no overlaps and no gaps.
Assigning types to objects restricts what operations make sense on them.
Objects often move through defined states — tracking these states enables workflow.
Classifying items by importance or urgency enables systematic decision-making.
Defining roles for people and objects clarifies what each is responsible for.
Lazy or inconsistent categorization creates a growing mess that eventually must be cleaned up.
Changing how you categorize things is a sign of learning not inconsistency.
Putting something in the wrong category means the wrong actions get applied to it.
How you sort things shows what dimensions matter to you.
Many real categories are organized around a central example rather than strict rules.
Items that do not fit neatly into any category expose weaknesses in your system.
Sometimes you need to classify the same items along multiple independent dimensions.
Categories reduce complexity by treating similar things as equivalent for a given purpose.
The best category systems adapt as you learn more about what you are organizing.