KDOS Domain Taxonomy v1.0

Core principles (read once)

  1. Domains are “what kind of knowledge this is”, not what it’s about.

  2. Domains change slowly; tags change freely.

  3. Every entry should have 1–3 domains, never more.

  4. If unsure between two domains:

    • Ask: which discipline would teach this?

Tier-1 Canonical Domains (lock these)

These are top-level, first-class domains.

1. Mathematics

Abstract structures, formal systems, proofs, and quantitative reasoning.

Examples:

  • Probability theory

  • Linear algebra

  • Optimization

  • Graph theory


2. Statistics

Inference, uncertainty, data modeling, and estimation.

Examples:

  • Bayesian updating

  • Hypothesis testing

  • Regression

  • Sampling theory


3. Computer Science

Computation, algorithms, software systems, and formal models of computing.

Examples:

  • Algorithms

  • Data structures

  • Operating systems

  • Compilers


4. Engineering

Applied technical design grounded in physical constraints.

Examples:

  • Electrical engineering

  • Mechanical systems

  • Control theory

  • Signal processing


5. Physics

Fundamental laws governing matter, energy, space, and time.

Examples:

  • Classical mechanics

  • Thermodynamics

  • Quantum theory

  • Electromagnetism


6. Chemistry

Structure, properties, and transformations of matter.

Examples:

  • Organic chemistry

  • Reaction kinetics

  • Materials chemistry


7. Biology

Living systems, from molecules to ecosystems.

Examples:

  • Genetics

  • Evolution

  • Physiology

  • Microbiology


8. Medicine

Clinical, diagnostic, and therapeutic knowledge.

Examples:

  • Pathophysiology

  • Pharmacology

  • Diagnostics

(Rule: use Medicine, not Biology, for clinical context.)


9. Economics

Production, exchange, incentives, and resource allocation.

Examples:

  • Microeconomics

  • Macroeconomics

  • Game theory

  • Monetary theory


10. Finance

Capital allocation, markets, risk, and valuation.

Examples:

  • Portfolio theory

  • Derivatives

  • Trading systems

  • Risk management


11. Philosophy

Foundational questions about reality, knowledge, ethics, and meaning.

Examples:

  • Epistemology

  • Metaphysics

  • Ethics

  • Philosophy of mind


12. History

Study of past events, civilizations, and temporal causation.

Examples:

  • Roman history

  • Industrial revolution

  • Intellectual history


13. Psychology

Mind, cognition, behavior, and affect.

Examples:

  • Cognitive bias

  • Learning theory

  • Psychometrics


14. Linguistics

Language structure, meaning, and evolution.

Examples:

  • Syntax

  • Semantics

  • Historical linguistics


15. Sociology

Social structures, institutions, and group behavior.

Examples:

  • Social networks

  • Institutions

  • Demographics


16. Anthropology

Human cultures, evolution, and material practices.

Examples:

  • Cultural anthropology

  • Archaeology

  • Ethnography


17. Law

Legal systems, doctrines, and jurisprudence.

Examples:

  • Contract law

  • Constitutional law

  • Legal theory


18. Political Science

Power, governance, political systems, and ideology.

Examples:

  • Political theory

  • Comparative politics

  • International relations


19. Ethics

Applied and normative moral reasoning.

(Separate from Philosophy when practical/decision-oriented.)

Examples:

  • Bioethics

  • Professional ethics

  • AI ethics


20. Logic

Formal reasoning systems and inference rules.

Examples:

  • Propositional logic

  • Predicate logic

  • Modal logic


21. Metaphysics

Ontology, causation, time, and existence.

(Used when topic is purely ontological rather than philosophical-historical.)


22. Epistemology

Theory of knowledge, belief, and justification.


23. Aesthetics

Theory of beauty, art, and perception.


24. Theology

Religious doctrines, systems, and metaphysical theology.


25. Mythology

Mythic narratives, symbols, and comparative myth.


26. Literature

Literary works, criticism, and narrative theory.


27. Education

Learning theory, pedagogy, and instructional systems.


28. Systems

General systems theory, cybernetics, complexity.

Examples:

  • Feedback loops

  • Emergence

  • System dynamics


29. Information Theory

Encoding, transmission, entropy, and signal limits.


30. Meta

Knowledge about knowledge.

Examples:

  • KDOS standards

  • Ontologies

  • Methodology

  • Research design


Explicit exclusions (important)

These are NOT domains — they are tags:

  • AI

  • Machine learning

  • Stoicism

  • Trading

  • Programming languages

  • Tools

  • Techniques

  • Schools of thought

Those go in tags.