28 kinds of knowledge cards, and when each one earns its place
Quadrants, funnels and timelines are not decoration. A mold is only used when the source genuinely has that shape — otherwise you are inventing a claim the author never made. This is our internal selection table.
PandaRead breaks a piece of content into cards, and cards come in 28 shapes: summary, argument, concept, comparison, timeline, process, quadrant, funnel, pyramid, relationship map, trend line, and so on.
The obvious question: what decides which one gets used?
The answer is simpler and stricter than people expect: whether the source actually has that structure.
One hard rule: never invent structure
Quadrants are seductive. Any two dimensions produce one, and any four ideas can be forced into the boxes — which is exactly what makes them dangerous.
Our rule: a mold is used only when the author organized the material that way. If the text says "high value / low cost, high value / high cost…", that is a quadrant. If the author merely listed four things, it is not. Forcing it does not "clarify" anything; it manufactures a claim the source never made, and the reader will assume the author made it.
The same goes for the rest:
- A timeline requires genuine chronology, not merely "A was discussed before B";
- A funnel requires real narrowing between stages, not parallel phases;
- A relationship map requires relations the author stated, not associations we guessed.
The selection table
| Shape the source presents | Mold |
|---|---|
| A thesis that fits in one sentence | Summary |
| An explicit claim plus its reasoning | Argument / chain of reasoning |
| A term you must define to keep reading | Concept (flip card) |
| A multi-dimensional comparison of A and B | Comparison table |
| Events in chronological order | Timeline |
| Actions with real dependencies | Process steps |
| Four classes cut by two dimensions | Quadrant |
| Stage-by-stage narrowing | Funnel |
| A hierarchy with a base and an apex | Pyramid |
| Relations among several parties | Relationship map |
| Values changing over time | Trend line |
| Before vs after a change | Before / after |
| A self-reinforcing loop | Flywheel / vicious cycle |
| A branching judgement | Decision tree |
| A line worth quoting verbatim | Pull quote |
| A conclusion carrying a number | Stat card |
Why 6–15 cards, and not as many as possible
An early version chased "no sentence left behind" and produced a screen-high wall of text. The user's verdict was blunt, and correct.
The principle since: cards curate; the full text handles completeness. If you want everything, the article pane has every word. If you want the skeleton fast, the cards must be few and precise.
Concretely: 6–8 for thin material, 10–15 for dense material, never above 15. Past fifteen, reading the cards costs the same attention as reading the original — at which point they have no reason to exist.
Every card must jump back to the source
This is not a layout preference. It is the foundation the product stands on.
A breakdown is probabilistic; it can be wrong. What makes it usable is not high accuracy but the fact that you can catch it being wrong: every card is anchored, and one click takes you to its paragraph in the text or its second in the video. Three seconds is enough to check whether we misread the author.
A summary you cannot trace back is asking for unconditional trust. We would rather not ask.