Software Evidence in a Minute
Evidence vs Assertion
The Factimonious distinction: assertions are claims; evidence is observable support for those claims.
In one sentence
An assertion is a claim about software; evidence is observable information that can support or weaken that claim.
Why it matters
AI-assisted delivery produces fluent assertions at high volume. Engineering trust requires matching each important claim to evidence—or labeling it as unknown.
How it works
- Write the claim as a falsifiable statement.
- Ask what artifact would count as support: commit, diff hunk, test output, metric, config, ticket, deploy record.
- Collect that artifact with enough provenance to re-find it.
- State the residual uncertainty explicitly.
- Refuse to upgrade “plausible” to “proven” without new evidence.
Example
Assertion: “The refactor reduced complexity.” Evidence candidates: before/after complexity measurements on the same scope, test suite delta, and a bounded diff. A longer commit message is not evidence of reduced complexity.
What this proves
Applying this distinction proves only that you have separated claim language from supporting artifacts—and that you know which claims still lack support.
What this does not prove
Having some evidence does not prove the strongest possible wording of the claim. Evidence for one facet (tests pass) does not prove another (users are happier).
Last reviewed 2026-09-06. Title for citation: Software Evidence in a Minute: Evidence vs Assertion.