Reconciliation

After this lesson, the reader should understand:

• 01Compare a documented rule and an observed rule without relying on text similarity.
• 02Derive the direction of a divergence from the geometry of the boundary.
• 03Classify a reconciliation outcome as faithful, divergent, or undocumented.

Comparing the wrong things

A policy rule reads "approve where the applicant meets the standard exposure test". An observed rule reads "approve where exposure ≤ 0.3". A text comparison scores them as closely related. Is the institution compliant?

The comparison cannot say, because it compared descriptions rather than boundaries. Two rules can share almost every significant word and impose entirely different thresholds; two rules can share no vocabulary at all and impose the same one. A reconciliation that means anything extracts a boundary from each side — the field, the threshold, and which side is permissive — and compares those. Normalise both to the same orientation, and the direction of any divergence then follows from arithmetic rather than interpretation: a shift that enlarges the permissive region is movement toward permissiveness, whatever the surrounding prose appears to say.

• What tolerance should count as agreement, and who is entitled to set it?
• Is an undocumented boundary a gap in the document, or in the practice?
• How should a reconciliation report a rule that is documented but never used?
• Why is "faithful" a result worth publishing?

Reconcile one field end to end.

1. 01Extract the documented boundary for one field.
2. 02Extract the observed boundary for the same field.
3. 03Normalise both to the same permissive orientation.
4. 04Classify the outcome: faithful, divergent, undocumented, or dormant.
5. 05If divergent, state direction and magnitude — without yet calling it good or bad.

• Conformance checking — fitness and precision measures (van der Aalst).
• Requirements engineering — bidirectional traceability.
• Measurement theory — tolerance and equivalence.
• Specification testing — the oracle problem.