Issue

Old Output Expectations Survive Migration

Expectations from a prior model, prompt, schema, tool, or workflow survive a migration and continue shaping review or downstream handling after they should be replaced.

What This Looks Like

A system migrates to a new model, prompt, schema, tool, or workflow, but old output expectations remain active. Reviewers, parsers, downstream tools, examples, documentation, or prompts may still assume the previous output shape, labels, level of detail, or behavior.

Why It Matters

Migrations can fail quietly when old expectations survive. The new system may be judged against obsolete requirements, or the old requirements may keep shaping prompts and review even though they no longer match the current design. This creates confusion about whether the new output is wrong or the old expectation is stale.

Structural Signal

A migration changes the intended output contract, but legacy expectations continue to govern part of the workflow. The issue is not simply that the output changed; it is that old expectations were not retired or reconciled with the new structure.

Common Triggers

Old examples remain in prompts or documentation
Parsers or validators still expect the previous format
Reviewers use prior rubric language after migration
Workflow metadata is not updated with the new output contract
Compatibility shims preserve legacy assumptions too long
Migration changes the generator but not the consumers

When to Use This Issue

Use this Issue when legacy output expectations continue to affect review, parsing, prompting, or downstream handling after a migration to a new model, schema, tool, prompt, or workflow.

When Not to Use This Issue

Do not use this Issue when the migration intentionally preserves the old output contract. Do not use it for ordinary output differences unless stale expectations are still governing the workflow.

Primary Pattern

PAT-0190 — Contract Drift

Declared Patterns

PAT-0190

Contract Drift

A structural condition where a declared contract changes but connected structures, implementations, consumers, or expectations do not update in sync.

PAT-0350

Persistence Instability

A structural condition where persisted state cannot be stored and restored into an equivalent structure without alteration.

PAT-0370

Redundant Declaration

A structural condition where multiple declarations produce equivalent structural effect without semantic differentiation.

Derived Primary Lenses

LEN-0150

Conflict Lens

Detects mutually incompatible constraints, claims, states, or declarations that cannot be simultaneously satisfied.

LEN-0170

Convergence Lens

Compares parallel structural systems to determine whether they align under shared authority.

LEN-0230

Normalization Lens

Transforms structurally equivalent variants into a canonical form to prevent false divergence.

LEN-0270

Reconciliation Lens

Evaluates whether structural changes align with declared authority updates, version changes, or reconciliation rules.

LEN-0280

Reference Stability Lens

Evaluates whether structural references, identifiers, nodes, and edges remain consistent across execution cycles or comparable states.

Derived Secondary Lenses

LEN-0140

Compression Lens

Reduces structural graphs into stable minimal representations for comparison, redundancy detection, and diffing.

LEN-0180

Determinism Lens

Evaluates whether identical structural inputs produce equivalent structural outputs across repeated executions.

Search Intents

old output expectations survive migration
old AI output format still expected
migration kept old output assumptions
workflow expects old model output
old schema expectations remain after migration
legacy output rules survived update