frontend-patterns/research/evolution/EvolutionReport.md

# Language evolution report

Generated by `make evolution-report`; curated assessment date: 2026-09-27.

This is an evidence profile, not a completion percentage. Evidence presence does not establish full-contract recurrence or production fitness.

The baseline profiles are author-model assessments by Codex; they do not confer independent validation.

## Current corpus

17 candidates: 17 hypothesis.

| Evidence attached to a candidate | Candidates |
| --- | ---: |
| documentary | 17 |
| static-code | 5 |
| runtime | 8 |

Categories overlap. Runtime includes authored fixtures and negative controls. Family labels group related evidence; they are not counts of independent applications.

Independent human profile reviews: 0/17. Full-contract independent-use counts unassessed: 17/17.

## Change since baseline

Baseline baseline-2026-09-26; source revision `f273a190f0e08b8cfe0bb7260d0e7d889f1c090a`. Added: 0; removed: 0; shared candidates with changed content: 2; changed evidence/review assessments: 2; maturity transitions: 0.

The shared cohort is compared separately from additions. Changed text or evidence counts are not learning gains.

## Applicability and usefulness

| Case | State |
| --- | --- |
| [VC-01](../../research/walkthroughs/VC01-TransactionalAdministration.md) | synthetic draft |
| [VC-02](../../research/walkthroughs/VC02-OfflineFieldNotes.md) | synthetic draft |
| [VC-03](../../research/walkthroughs/VC03-ContentPublication.md) | provisional |
| [VC-04](../../research/plan/ValidationCases.md) | planned |
| [VC-05](../../research/plan/ValidationCases.md) | planned |
| [VC-06](../../research/walkthroughs/VC06-MicrofrontendEstate.md) | provisional |
| [VC-07](../../research/plan/ValidationCases.md) | planned |
| [VC-08](../../research/plan/ValidationCases.md) | planned |
| [VC-09](../../research/plan/ValidationCases.md) | planned |
| [VC-10](../../research/plan/ValidationCases.md) | planned |

Frozen pilot after adjudication: named 18/24; prose 18/24. Initial unsupported-claim count: 2 per condition (historical only); adjudicated flags remain qualitative, with no revised numeric count. Independent human validation: pending. Decision time: unknown. [Adjudication](../../research/evaluations/language-pilot-01/submitted-review-01/adjudication.md).

One frozen development pilot with submitted model review; six matched briefs. Equal aggregate scores do not establish equivalence. Stable anchors are consumed development cases, not fresh held-out tasks.

## Learning and effort

Ten selected retrospective outcomes (not a historical census), followed by prospectively registered bounded cycles. Retrospective effort remains unknown.

| Outcome | Entries (not independent discoveries) |
| --- | ---: |
| corroboration | 1 |
| inconclusive | 0 |
| merge | 0 |
| rejection | 0 |
| revision | 10 |

Cycles with recorded research effort: 1/11. Unknown effort is neither zero nor estimated from commits, tokens or assertion counts.

### Stream B / B-navigation-mechanism-v1

| Cycle | Outcome | Research minutes | Consequential outcome/hour |
| --- | --- | ---: | ---: |
| LEARN-0011 | corroboration | 6.177 | 0.00 |

One bounded question counts at most one consequential outcome. Corroboration and inconclusive work remain visible separately. Fewer than three comparable cycles: no trend assessment.

## Coherence and maintainability

Profile hashes and local references passed validation when this report was generated. That checks traceability, not source truth or external URL freshness.

Profiles with unknown last substantive review date: 15. Assessment dates record this metadata review, not a new substantive validation. No age-based freshness claim is available for those profiles.

Coherence metrics (ambiguous selections, unjustified relations and overlap resolved): not measured. Conflict Copy / Explicit Reconciliation overlap remains an explicit open question.

Review backlog and evidence gaps remain in [FEP-WP-0002-seed-language-validation](../../workplans/FEP-WP-0002-seed-language-validation.md), [FEP-WP-0003-contrasting-schools](../../workplans/FEP-WP-0003-contrasting-schools.md), [FEP-WP-0006-language-evolution](../../workplans/FEP-WP-0006-language-evolution.md).

## Pattern profiles

### CAND-0001 — Conflict Copy

[ConflictCopy](../../research/candidates/ConflictCopy.md) · draft / hypothesis

Preserve competing versions instead of silently losing one.

| Evidence | Family | Scope | Review |
| --- | --- | --- | --- |
| documentary | Joplin | Documented detected-note conflict copy. | [LocalFirstEvidenceExpansion](../../research/reviews/LocalFirstEvidenceExpansion.md) |
| documentary | Obsidian | Optional conflict-file mode, not default behavior. | [LocalFirstEvidenceExpansion](../../research/reviews/LocalFirstEvidenceExpansion.md) |

Open limits: Authorized retention and export are separate decisions. Complete contract recurrence and fault-tested deployed behavior remain unverified.

Superseded by: none recorded.

### CAND-0002 — Local Commit Boundary

[LocalCommitBoundary](../../research/candidates/LocalCommitBoundary.md) · draft / hypothesis

Define when a local change is durably accepted.

| Evidence | Family | Scope | Review |
| --- | --- | --- | --- |
| documentary | Ink & Switch | Local-first motivation. | [LocalFirstEvidenceExpansion](../../research/reviews/LocalFirstEvidenceExpansion.md) |
| documentary | Joplin | Local storage and synchronization architecture. | [LocalFirstEvidenceExpansion](../../research/reviews/LocalFirstEvidenceExpansion.md) |

Open limits: No executed storage crash or backup test. Local acceptance is not off-device recovery.

Superseded by: none recorded.

### CAND-0003 — Pending Synchronization

[PendingSynchronization](../../research/candidates/PendingSynchronization.md) · draft / hypothesis

Keep accepted local intent visible until synchronization resolves.

| Evidence | Family | Scope | Review |
| --- | --- | --- | --- |
| documentary | Joplin | Per-item synchronization metadata. | [LocalFirstEvidenceExpansion](../../research/reviews/LocalFirstEvidenceExpansion.md) |

Open limits: Atomic supersession and retry contract proposed, not storage-tested.

Superseded by: none recorded.

### CAND-0004 — Explicit Reconciliation

[ExplicitReconciliation](../../research/candidates/ExplicitReconciliation.md) · draft / hypothesis

Resolve divergent content while retaining provenance.

| Evidence | Family | Scope | Review |
| --- | --- | --- | --- |
| documentary | Joplin | Documented manual conflict resolution. | [LocalFirstEvidenceExpansion](../../research/reviews/LocalFirstEvidenceExpansion.md) |
| documentary | Obsidian | Conflict comparison workflow. | [LocalFirstEvidenceExpansion](../../research/reviews/LocalFirstEvidenceExpansion.md) |

Open limits: Atomic resolution/provenance UI not executed. Overlap with Conflict Copy remains an open merge question.

Superseded by: none recorded.

### CAND-0005 — Local Draft State

[LocalDraftState](../../research/candidates/LocalDraftState.md) · draft / hypothesis

Separate unfinished intent from refreshed authoritative data.

| Evidence | Family | Scope | Review |
| --- | --- | --- | --- |
| documentary | Kubernetes / GitLab / React Router | Rejection and pending-input mechanisms motivate recovery. | [TransactionalEvidenceExpansion](../../research/reviews/TransactionalEvidenceExpansion.md) |
| static-code | Zulip | Pinned composer draft storage; partial lifecycle. | [FrontendRecoveryImplementations](../../research/reviews/FrontendRecoveryImplementations.md) |
| static-code | Element / Matrix | Pinned composer draft restoration; partial lifecycle. | [FrontendRecoveryImplementations](../../research/reviews/FrontendRecoveryImplementations.md) |
| runtime | authored release fixture | Same-tab preservation/refusal/discard and post-navigation schema check. | [ActivationConflictsAndReload](../../research/reviews/ActivationConflictsAndReload.md) |

Open limits: No native-unload, crash, multiple-tab or access-revocation guarantee. Full base/draft/current merge contract is not verified in deployed frontends.

Superseded by: none recorded.

### CAND-0006 — Version-Checked Mutation

[VersionCheckedMutation](../../research/candidates/VersionCheckedMutation.md) · draft / hypothesis

Reject an operation whose observed base is stale.

| Evidence | Family | Scope | Review |
| --- | --- | --- | --- |
| documentary | Kubernetes | Conditional PUT; precise version mechanism. | [TransactionalEvidenceExpansion](../../research/reviews/TransactionalEvidenceExpansion.md) |
| documentary | GitLab | Optional last_commit_id; different failure surface. | [TransactionalEvidenceExpansion](../../research/reviews/TransactionalEvidenceExpansion.md) |
| runtime | authored release fixture | Related conditional activation-map mechanism in one process, not the full frontend pattern. | [ActivationConflictsAndReload](../../research/reviews/ActivationConflictsAndReload.md) |

Open limits: Distributed atomicity and complete frontend recurrence remain unverified. Refetch does not authorize overwriting conflicting intent.

Superseded by: none recorded.

### CAND-0007 — Mutation Outcome Tracking

[MutationOutcomeTracking](../../research/candidates/MutationOutcomeTracking.md) · draft / hypothesis

Retain operation identity when transport outcome is uncertain.

| Evidence | Family | Scope | Review |
| --- | --- | --- | --- |
| documentary | Stripe | Idempotency mechanism. | [TransactionalEvidenceExpansion](../../research/reviews/TransactionalEvidenceExpansion.md) |
| documentary | React Router | Cancellation does not imply server rollback. | [TransactionalEvidenceExpansion](../../research/reviews/TransactionalEvidenceExpansion.md) |
| static-code | Zulip | Pinned send/recovery state. | [FrontendRecoveryImplementations](../../research/reviews/FrontendRecoveryImplementations.md) |
| static-code | Element / Matrix | Pinned client and SDK transaction/echo paths. | [FrontendRecoveryImplementations](../../research/reviews/FrontendRecoveryImplementations.md) |
| runtime | Element / Matrix | Real SDK with synthetic transport: lost acknowledgement, identity reuse and authoritative echo. | [MatrixRecoveryExperiment](../../research/reviews/MatrixRecoveryExperiment.md) |

Open limits: No production server deduplication or complete retention-window guarantee. Cancelling local UI is not remote compensation.

Superseded by: none recorded.

### CAND-0008 — Invalidate and Reproject

[InvalidateAndReproject](../../research/candidates/InvalidateAndReproject.md) · draft / hypothesis

Refresh a projection after mutation without equating acceptance and visibility.

| Evidence | Family | Scope | Review |
| --- | --- | --- | --- |
| documentary | React Router | Concurrency and pending-state guidance. | [TransactionalEvidenceExpansion](../../research/reviews/TransactionalEvidenceExpansion.md) |

Open limits: Read-your-write and acceptance/refresh distinction still proposed. No independent deployed full-contract observation.

Superseded by: none recorded.

### CAND-0009 — URL-addressable State

[URLAddressableState](../../research/candidates/URLAddressableState.md) · draft / hypothesis

Make a navigable state reconstructible from its URL.

| Evidence | Family | Scope | Review |
| --- | --- | --- | --- |
| documentary | htmx | History behavior and history-cache misses. | [NavigationRenderingEvidence](../../research/reviews/NavigationRenderingEvidence.md) |
| documentary | Web platform | pushState changes history, not server dereferenceability. | [NavigationRenderingEvidence](../../research/reviews/NavigationRenderingEvidence.md) |
| runtime | htmx in authored public-catalog fixture | NH01–NH06: native/enhanced routes, history hit/miss, actual browser cache ordering and missing-Vary negative control; explicit Node validator checks separate. | [NavigationHistoryExperiment](../../research/reviews/NavigationHistoryExperiment.md) |

Open limits: Independent deployed full-contract recurrence remains unverified. Keyboard/focus/announcements, late-script activation, interrupted transport, invalid/deleted routes, offline availability and real intermediary behavior remain open.

Superseded by: none recorded.

### CAND-0010 — Progressive Enhancement

[ProgressiveEnhancement](../../research/candidates/ProgressiveEnhancement.md) · draft / hypothesis

Keep essential actions usable when enhancement is unavailable.

| Evidence | Family | Scope | Review |
| --- | --- | --- | --- |
| documentary | htmx | Boosted links and forms. | [NavigationRenderingEvidence](../../research/reviews/NavigationRenderingEvidence.md) |
| documentary | SvelteKit | Form actions and rendering/page options. | [NavigationRenderingEvidence](../../research/reviews/NavigationRenderingEvidence.md) |
| runtime | htmx in authored public-catalog fixture | NH01–NH06: native/enhanced routes, history hit/miss, actual browser cache ordering and missing-Vary negative control; explicit Node validator checks separate. | [NavigationHistoryExperiment](../../research/reviews/NavigationHistoryExperiment.md) |

Open limits: Independent deployed full-contract recurrence remains unverified. Keyboard/focus/announcements, late-script activation, interrupted transport, invalid/deleted routes, offline availability and real intermediary behavior remain open.

Superseded by: none recorded.

### CAND-0011 — Presentation Model

[PresentationModel](../../research/candidates/PresentationModel.md) · draft / hypothesis

Separate presentation decisions from view mechanisms.

| Evidence | Family | Scope | Review |
| --- | --- | --- | --- |
| documentary | Fowler | Named pattern and illustrative model/view discussion. | [PatternBreadthExpansion](../../research/reviews/PatternBreadthExpansion.md) |

Open limits: No executed model/view integration or independently reviewed full-contract use.

Superseded by: none recorded.

### CAND-0012 — Derived State

[DerivedState](../../research/candidates/DerivedState.md) · draft / hypothesis

Compute a result from explicit authoritative inputs.

| Evidence | Family | Scope | Review |
| --- | --- | --- | --- |
| documentary | Redux | Selector guidance, not a requirement for a global store. | [PatternBreadthExpansion](../../research/reviews/PatternBreadthExpansion.md) |

Open limits: Snapshot coherence and changed-locale cache test still planned.

Superseded by: none recorded.

### CAND-0013 — Vertical Feature Slice

[VerticalFeatureSlice](../../research/candidates/VerticalFeatureSlice.md) · draft / hypothesis

Group a capability across UI, state and behavior with explicit interfaces.

| Evidence | Family | Scope | Review |
| --- | --- | --- | --- |
| documentary | Feature-Sliced Design | Layer/slice and public-interface guidance. | [PatternBreadthExpansion](../../research/reviews/PatternBreadthExpansion.md) |
| static-code | Feature-Sliced Design | Pinned todo-app interfaces coexist with one application build. | [FeatureDeploymentBoundaries](../../research/reviews/FeatureDeploymentBoundaries.md) |

Open limits: Build/import enforcement not executed. Feature organization does not establish independent activation.

Superseded by: none recorded.

### CAND-0014 — Islands of Interactivity

[IslandsOfInteractivity](../../research/candidates/IslandsOfInteractivity.md) · draft / hypothesis

Activate selected interactive regions within a document.

| Evidence | Family | Scope | Review |
| --- | --- | --- | --- |
| documentary | Astro | Client-island mechanism and execution placement. | [PatternBreadthExpansion](../../research/reviews/PatternBreadthExpansion.md) |

Open limits: No executed island fixture, performance comparison or complete recurrence study.

Superseded by: none recorded.

### CAND-0015 — Failure Boundary

[FailureBoundary](../../research/candidates/FailureBoundary.md) · draft / hypothesis

Contain specified failure classes while preserving useful neighboring work.

| Evidence | Family | Scope | Review |
| --- | --- | --- | --- |
| documentary | React | Error boundary scope and exclusions. | [PatternBreadthExpansion](../../research/reviews/PatternBreadthExpansion.md) |
| runtime | React | Real package in authored host: render/event/request distinction and fallback escalation. | [BoundaryRecoveryExperiment](../../research/reviews/BoundaryRecoveryExperiment.md) |

Open limits: Synthetic host, not full application recurrence. Boundary cannot imply containment for all asynchronous failures.

Superseded by: none recorded.

### CAND-0016 — Focus Return

[FocusReturn](../../research/candidates/FocusReturn.md) · draft / hypothesis

Restore meaningful focus after a temporary interaction ends.

| Evidence | Family | Scope | Review |
| --- | --- | --- | --- |
| documentary | WAI-ARIA APG | Dialog focus obligations. | [PatternBreadthExpansion](../../research/reviews/PatternBreadthExpansion.md) |
| static-code | Radix | Pinned layer/listener ownership implementation. | [NestedDismissalIsolation](../../research/reviews/NestedDismissalIsolation.md) |
| runtime | Radix | Authored fixture: raw 20/24 versus routed 24/24; browser/build limits retained. | [NestedOwnershipRouting](../../research/reviews/NestedOwnershipRouting.md) |

Open limits: One implementation family; repeated trials are not independent uses. Animated exits and competing owners remain untested; no production repair claim.

Superseded by: none recorded.

### CAND-0017 — Independent Feature Boundary

[IndependentFeatureBoundary](../../research/candidates/IndependentFeatureBoundary.md) · draft / hypothesis

Separate feature release, activation and session transition contracts.

| Evidence | Family | Scope | Review |
| --- | --- | --- | --- |
| documentary | single-spa / webpack | Mechanism documentation, not deployed independence proof. | [FeatureDeploymentBoundaries](../../research/reviews/FeatureDeploymentBoundaries.md) |
| static-code | react-microfrontends examples | Root config/navbar are one example family with shared startup gating. | [FeatureDeploymentBoundaries](../../research/reviews/FeatureDeploymentBoundaries.md) |
| runtime | authored release fixture | Publication/activation/rollback across fresh, loaded and lazy sessions. | [FeatureReleaseExperiment](../../research/reviews/FeatureReleaseExperiment.md) |
| runtime | authored release fixture | Conditional activation updates and safe reload policies, including negative controls. | [ActivationConflictsAndReload](../../research/reviews/ActivationConflictsAndReload.md) |

Open limits: No upstream deployment or real team/release-independence validation. Distributed atomicity, retention authorization and native-unload/crash behavior remain open.

Superseded by: none recorded.

## Recorded learning

### LEARN-0001 — What do pinned recovery implementations establish?

2026-09-25 · stream D · retrospective · revision

Before: Documentary motivation did not locate draft/outcome mechanisms in frontend code.

Conclusion: Zulip and Element locate partial draft/outcome mechanisms; complete pattern recurrence is still unknown.

Evidence: [FrontendRecoveryImplementations](../../research/reviews/FrontendRecoveryImplementations.md).

Remaining uncertainty: Deployed full lifecycle remains unverified.

Supersedes: none recorded.

### LEARN-0002 — Does cancellation or a transport error settle mutation outcome?

2026-09-25 · stream D · retrospective · revision

Before: Recovery identity and authoritative echo required executable checks.

Conclusion: Synthetic transport with the real Matrix SDK distinguishes replay identity, duplicate commits and authoritative echo.

Evidence: [MatrixRecoveryExperiment](../../research/reviews/MatrixRecoveryExperiment.md).

Remaining uncertainty: No real server deduplication guarantee.

Supersedes: none recorded.

### LEARN-0003 — Does naming patterns improve the frozen pilot decisions?

2026-09-26 · stream cross-stream · retrospective · revision

Before: Initial editorial scores were 21/24 named and 19/24 prose.

Conclusion: Submitted model review adjudication yields 18/24 in each condition; this does not establish equivalence or a presentation benefit.

Evidence: [adjudication](../../research/evaluations/language-pilot-01/submitted-review-01/adjudication.md).

Remaining uncertainty: Independent human validation pending. Historical effort unknown; this entry does not allocate whole-pilot telemetry.

Supersedes: none recorded.

### LEARN-0004 — Which recovery recommendations overstate their guarantees?

2026-09-26 · stream D · retrospective · revision

Before: Shared guidance left retention/export policy, cancellation and local backup boundaries insufficiently explicit.

Conclusion: Guidance now separates authorization, remote compensation, atomic supersession and off-device backup.

Evidence: [SharedGuidanceRevision](../../research/reviews/SharedGuidanceRevision.md).

Remaining uncertainty: Editorial correction is not new production evidence.

Supersedes: none recorded.

### LEARN-0005 — What does URL/history and enhancement documentation actually promise?

2026-09-26 · stream B · retrospective · revision

Before: Navigation and rendering seeds lacked explicit dereferenceability and fallback distinctions.

Conclusion: Developed two hypotheses separating address-bar updates from direct loads, and HTML delivery from usable no-script actions.

Evidence: [NavigationRenderingEvidence](../../research/reviews/NavigationRenderingEvidence.md).

Remaining uncertainty: Navigation/history/cache runtime checks remain pending.

Supersedes: none recorded.

### LEARN-0006 — Why can immediate nested dismissal close the outer task?

2026-09-26 · stream F · retrospective · revision

Before: The first fixture exposed a timing failure with unresolved ownership.

Conclusion: Trace locates stale Escape listener ownership despite inner registration/focus; a guard can lose input.

Evidence: [BoundaryRecoveryExperiment](../../research/reviews/BoundaryRecoveryExperiment.md), [NestedDismissalIsolation](../../research/reviews/NestedDismissalIsolation.md).

Remaining uncertainty: Readiness waits are not a public product repair.

Supersedes: none recorded.

### LEARN-0007 — Can event-time ownership route dismissal without a settling delay?

2026-09-26 · stream F · retrospective · revision

Before: Isolation supplied a mechanism but no lifecycle-safe candidate routing experiment.

Conclusion: Controlled fixture routed 24/24 versus raw 20/24; initial measurement error and corrected results retained.

Evidence: [NestedOwnershipRouting](../../research/reviews/NestedOwnershipRouting.md).

Remaining uncertainty: Animated exit and competing-owner coverage remain open.

Supersedes: none recorded.

### LEARN-0008 — Are feature organization and independent activation the same boundary?

2026-09-26 · stream E · retrospective · revision

Before: The feature-slice hypothesis needed a source-layout/release contrast.

Conclusion: Pinned examples distinguish organizational slicing from activation contracts; added Independent Feature Boundary.

Evidence: [FeatureDeploymentBoundaries](../../research/reviews/FeatureDeploymentBoundaries.md).

Remaining uncertainty: Shared startup dependencies still couple nominally separate features.

Supersedes: none recorded.

### LEARN-0009 — Does publication or rollback update every session?

2026-09-26 · stream E · retrospective · revision

Before: Static source review could not establish loaded/lazy-session behavior.

Conclusion: Native-module experiment distinguishes publication, activation and already-bound sessions; artifact retirement breaks old lazy sessions.

Evidence: [FeatureReleaseExperiment](../../research/reviews/FeatureReleaseExperiment.md).

Remaining uncertainty: No CDN or upstream deployment validation.

Supersedes: none recorded.

### LEARN-0010 — How do stale activation writers and unfinished drafts constrain updates?

2026-09-26 · stream E · retrospective · revision

Before: Release experiment left activation conflicts and reload policy unexecuted.

Conclusion: Conditional replacement rejects stale writers; explicit reload policies preserve or refuse transition, with schema recheck after navigation.

Evidence: [ActivationConflictsAndReload](../../research/reviews/ActivationConflictsAndReload.md).

Remaining uncertainty: One-process atomicity; no native unload, crash or real remote-outcome coverage.

Supersedes: none recorded.

### LEARN-0011 — Can a public route preserve selection and complete-document availability across native/enhanced entry, history and HTTP caching?

2026-09-27 · stream B · prospective · corroboration

Before: Native href/GET contracts plus representation-aware routing and cache selection should satisfy this narrow obligation; documentary support lacked runtime checks.

Conclusion: Corroborated in pinned htmx fixture: native and history paths work; missing Vary reproduces fragment-as-document reuse in both browsers. Existing obligations stand; no new pattern or promotion.

Evidence: [NavigationHistoryExperiment](../../research/reviews/NavigationHistoryExperiment.md), [result](../../research/experiments/navigation-history/result.json), [2026-09-27-navigation-effort](../../research/evolution/cycles/2026-09-27-navigation-effort.json).

Remaining uncertainty: One authored application, no independent recurrence or usefulness gain. Accessibility, delayed scripts, interrupted transport, real intermediaries and offline availability remain open.

Supersedes: none recorded.