The PKM Stack is a layered framework for modeling how information flows through a personal knowledge system. Developed by Mike Schmitz and Aidan Helfant, it positions layers from bottom to top: Information, Ideas, Actions, and Philosophy (vision/values), with Reflection as the connective tissue running through all layers.
The Layers
- Information (base) — Raw inputs: highlights, clippings, references, facts. The unprocessed material that enters your system from reading, listening, and observing.
- Ideas — Processed information: connections, insights, original thoughts. Information becomes an idea when you add interpretation, link it to existing knowledge, or reframe it in your own words.
- Actions — Decisions and tasks driven by ideas. Ideas become actionable when they inform what you do: projects you start, habits you adopt, content you create.
- Philosophy (top) — Your values, vision, and identity. The layer that determines what information is worth capturing, what ideas matter, and what actions are worth taking.
- Reflection (connective) — The practice that moves material between layers and keeps the stack coherent. Without reflection, layers accumulate independently and never integrate.
Archival vs Generative Information
The model makes a critical distinction between two types of information:
- Archival information — Stored and retrieved top-down via search. Reference material, receipts, documents, contact details. You know what you are looking for and you go find it. Folder hierarchies and search work well here.
- Generative information — Needs to bubble up bottom-up via intentional linking and connection-making. Ideas, insights, half-formed thoughts. You do not know what you are looking for until connections surface it.
This distinction explains a persistent debate in PKM: why bidirectional linking matters for idea development but is overkill for reference storage. The stack model resolves this by acknowledging that different types of information need different architectural affordances.
Values-Driven Architecture
The Philosophy layer at the top is not decorative. It actively filters and directs the layers below. Your values determine what information passes your resonance filter. Your vision determines which ideas get developed into actions. Without a defined philosophy layer, the stack drifts — you capture indiscriminately, generate ideas without direction, and take actions without coherence.
Key Points
- Four layers (Information, Ideas, Actions, Philosophy) with Reflection as connective tissue
- Archival information flows top-down (search); generative information flows bottom-up (linking)
- This distinction resolves the folder-vs-links debate — both are correct for different information types
- The Philosophy layer drives all downstream decisions about capture, development, and action
- Reflection is what prevents the layers from operating as disconnected silos
Open Questions
- How do you build the Philosophy layer if you have not articulated your values yet?
- Does the stack model apply to team knowledge management or only personal systems?
- Where does AI-assisted processing fit — does it compress the Information-to-Ideas transition?
References
- Mike Schmitz — PKM Stack model
- Aidan Helfant — PKM Stack model