PSD.10:4.2 - Represent what is unknown at its actual kind

Choose a form that answers the live question without claiming more knowledge than exists.

Available basis	Useful representation	Limit that must remain visible
Qualified stochastic model or elicited probabilistic judgement.	A distribution or probability statement tied to its event, population, conditions, and horizon.	Calibration, sampling, elicitation, model assumptions, and applicability still matter. Confidence in the analyst is not the event probability.
Supported bounds but no distribution.	An interval or set of admissible values.	An interval is not a uniform distribution; state what supports its endpoints and what lies outside its claim.
Several materially different models or future conditions.	Conditional claims under named models or scenarios.	Their count or frequency in an ensemble does not supply real-world likelihood.
A decisive absent result or unrepresented mechanism.	The exact missing claim and the comparison it prevents.	A blank cell is neither zero effect nor equal performance.
Incompatible interpretations, preferences, or authority claims.	Attributed alternatives and the unresolved interpretation or judgement.	Statistical uncertainty reduction alone cannot reconcile them.

These are use choices, not a universal taxonomy of uncertainty. Different forms may coexist in one account. Distinguish a physical or behavioral variability claim from uncertainty about its model, data, or applicability whenever the distinction changes the return.

If a probability is useful but unsupported, state the conditional comparison it would enable and identify the needed basis. Do not assign equal probabilities to scenarios simply to make an expected-value calculation run.