# One-page fact-versus-assumption guide

The single discipline this protocol adds is the line between a **fact** and an
**assumption**. Draw it for every statement before it enters the memo. A fact goes
in the Facts section and carries its source; an assumption goes in the Assumptions
section and is labelled as one. When a statement could be either, treat it as an
assumption and say why.

## The two categories

**fact** — Something a supplied source states as measured or as having happened.
- Test: can you point to the sentence in a source that asserts it?
- Example: "The contract expires on 31 March 2026" (the assessment says so).
- A fact is only as good as its source; a fact from one unaudited source is still a
  fact, but its *confidence* should reflect that.

**assumption** — A premise the reasoning depends on that the materials do not
themselves establish.
- Test: if this turned out false, would the conclusion change? And do the materials
  actually show it is true?
- Example: "Record volume stays near today's level through the migration" — the plan
  needs it, but no source establishes it.
- Surface assumptions explicitly and say what makes each one false. A hidden
  assumption is how a memo misleads while every stated fact is individually true.

## The traps that turn an assumption into a "fact"

- **A projection read as a measurement.** "Volume will hold" is about the future; the
  source only measured the past. Future-tense quantities are assumptions.
- **Arithmetic dressed as data.** A number you computed from supplied figures is a
  derived estimate resting on its inputs, not a new independent fact. If the inputs
  are assumptions, so is the result.
- **A silence filled from general knowledge.** If the materials do not cover a point,
  the honest move is to name the gap or carry an assumption — not to supply an
  outside fact and source it to nothing.
- **An opinion promoted to a fact.** "The fields do not matter" is a judgement until a
  source establishes it. Attribute it, or carry it as an assumption.

## Confidence is separate from category

Category says *whether the materials establish it*; confidence says *how firmly*. A
fact from a single unaudited source may be `medium`; a fact corroborated by two
sources may be `high`. Never let a confident tone stand in for a source — if the
materials are thin, say so in the confidence and the limitations.

## Tie each option to what it depends on

Once facts and assumptions are separated, an option's risk is visible: it is the set
of assumptions the option needs to be true. Record, for each option, the facts and
assumptions it is most sensitive to. An option that depends only on firm facts is
safer than one that depends on an untested assumption — and the memo should let the
reader see which is which.

## Mark reversibility before anyone commits

Separately from how likely an option is to work, ask how hard it is to undo. A
reversible action tolerates a wrong assumption; an irreversible one does not. Mark
each action, and put the human checkpoint before any irreversible commitment, so a
person confirms the facts and assumptions before a one-way door is opened.
