# AI Wiki - PKM - Progressive Summarization Progressive summarization is a technique developed by Tiago Forte for distilling captured information into increasingly compressed and useful forms. Rather than processing a note completely at capture time, you add layers of highlighting and summarization over multiple encounters, each time making the core ideas more visible. ## The Problem It Solves When you capture information (highlights from a book, notes from a meeting, excerpts from an article), you face a dilemma: - **Process it fully now** — Time-consuming and interrupts your current work. You may also lack the context to know what is most important. - **Save it for later** — Fast, but "later" rarely comes. The note becomes a graveyard of unprocessed text. Progressive summarization resolves this by spreading the processing across multiple encounters. Each encounter takes minimal effort but adds a layer of distillation. ## The Five Layers ### Layer 0: Original Full Text The raw source material. An article, book chapter, transcript, or any captured text. ### Layer 1: Saved Passages The act of capturing specific passages into your notes. You have already filtered by selecting only what resonated. This is the output of [[AI Wiki - PKM - The Capture Habit]]. ### Layer 2: Bold Passages On your next encounter with the note, bold the key sentences. This takes seconds and instantly makes the core points stand out. ### Layer 3: Highlighted Passages On a subsequent encounter, highlight (or use a different color) the most critical phrases within the bolded text. Now you have a three-level hierarchy of importance. ### Layer 4: Executive Summary Write a brief summary at the top of the note in your own words. This is the highest compression: the entire note distilled to a few sentences. ### Layer 5: Remix Use the distilled material to create something new: a blog post, a presentation, a project deliverable. This is the "Express" step in [[AI Wiki - PKM - Building a Second Brain]]'s CODE framework. ## Key Principles **Just-in-time processing.** Do not try to reach Layer 4 on first contact. Process only as far as the current moment requires. If you are just capturing for future reference, stop at Layer 1. If you are preparing for a project, go to Layer 3 or 4. **Each layer takes seconds, not minutes.** Bolding key sentences in a note you are revisiting takes 30 seconds. This low cost is what makes the system sustainable. **Not every note reaches every layer.** Most notes stay at Layer 1 or 2. Only the notes that prove their value through repeated relevance earn deeper processing. This is a natural quality filter. **Visual hierarchy matters.** The layering creates a visual scanability. When you return to a note months later, the bold and highlighted passages let you instantly grasp the key points without re-reading the full text. ## Relationship to Other Methods Progressive summarization is the "Distill" step in Tiago Forte's CODE framework ([[AI Wiki - PKM - Building a Second Brain]]). It complements the [[AI Wiki - PKM - Zettelkasten Method]] by providing a technique for processing literature notes before extracting permanent notes from them. The technique is particularly powerful for literature notes and source material. [[AI Wiki - PKM - Atomic Notes]] (permanent notes) do not typically need progressive summarization because they are already distilled to one idea. ## Key Points - Process captured material across multiple encounters, not all at once - Five layers: full text → saved passages → bold → highlight → executive summary → remix - Each layer takes seconds; not every note reaches every layer - Just-in-time processing; go only as deep as the current need requires - Creates visual scanability for future revisits ## Open Questions - Can AI perform Layers 2-4 automatically, or does the human processing step have irreplaceable cognitive value? - How does progressive summarization interact with spaced repetition? ## References - Tiago Forte, "Building a Second Brain" (2022) - Tiago Forte, "Progressive Summarization: A Practical Technique for Designing Discoverable Notes" (Forte Labs blog) - Vault: Progressive summarization ## Related - [[AI Wiki - PKM - Building a Second Brain]] - [[AI Wiki - PKM - The Capture Habit]] - [[AI Wiki - PKM - Note-Taking Taxonomy]] - [[AI Wiki - PKM - Atomic Notes]] - [[AI Wiki - PKM - Cognitive Science of PKM]] - [[AI Wiki - PKM - Information Diet]] - [[AI Wiki - PKM - Knowledge Lifecycle]]