[Doc] PR policy and Review Guidelines

CONTRIBUTING.md

@@ -156,5 +156,6 @@ Apache Mahout includes several subprojects. Use the root workflow above for issu
 
 - [testing/README.md](testing/README.md) — Test structure and commands
 - [.github/PULL_REQUEST_TEMPLATE](.github/PULL_REQUEST_TEMPLATE) — PR description template
+- [docs/community/pr-policy-and-review-guidelines.md](docs/community/pr-policy-and-review-guidelines.md) — PR policy and review guidelines (ASF-aligned)
 - [docs/](docs/) — Documentation source (used by the website)
 - [qdp/DEVELOPMENT.md](qdp/DEVELOPMENT.md) — QDP setup, tests, benchmarks, profiling

docs/community/pr-policy-and-review-guidelines.md

@@ -0,0 +1,144 @@
+<!--
+Licensed to the Apache Software Foundation (ASF) under one or more
+contributor license agreements.  See the NOTICE file distributed with
+this work for additional information regarding copyright ownership.
+The ASF licenses this file to You under the Apache License, Version 2.0
+(the "License"); you may not use this file except in compliance with
+the License.  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+-->
+
+---
+title: PR Policy and Review Guidelines
+sidebar_label: PR Policy & Review
+---
+
+# PR Policy and Review Guidelines
+
+This document defines Apache Mahout's pull request and review process, aligned with ASF principles of openness, consensus, and merit.
+
+## Scope
+
+These rules apply to all pull requests in `apache/mahout`, including code, tests, CI, and documentation.
+
+## Core Principles
+
+- Discuss significant changes in public (GitHub issue and/or `dev@mahout.apache.org`).
+- Keep decisions transparent and archived in project systems.
+- Prefer small, reviewable PRs over large multi-purpose changes.
+- Resolve technical disagreement through evidence, tests, and community discussion.
+
+## Contributor Requirements
+
+Before opening a PR:
+
+- Link to an issue when applicable.
+- Follow the PR template in [`PULL_REQUEST_TEMPLATE`](https://github.com/apache/mahout/blob/main/.github/PULL_REQUEST_TEMPLATE).
+- Include tests for behavior changes.
+- Update docs for user-visible changes.
+- Ensure CI and required checks pass.
+
+For non-trivial code contributions, contributors are expected to have an ASF ICLA on file.
+
+## PR Author Guidelines
+
+- Keep PRs focused on one concern (bug fix, feature slice, refactor, docs, etc.).
+- Describe `Why` and `How` clearly in the PR description.
+- Mark breaking or risky changes explicitly.
+- Respond to review feedback promptly and keep discussion on the PR thread.
+- Do not force-push in ways that hide review context after substantial review has started.
+
+## Review Expectations
+
+### General
+
+- Anyone in the community can review and comment.
+- CODEOWNERS define suggested reviewers, not exclusive authority.
+- Reviewers should focus on correctness, API/UX impact, test coverage, security, and maintainability.
+
+### For Contributors and Reviewers
+
+- Treat review comments as collaborative feedback.
+- Resolve open questions with tests, benchmarks, or design rationale when possible.
+- Keep review discussion on the PR thread so decisions are public and traceable.
+
+### Committer Merge Criteria (Committers Only)
+
+When deciding whether to merge, committers should verify all of the following:
+
+- Required CI checks are green.
+- At least one committer approves.
+- All blocking comments are resolved.
+
+The following changes should receive at least two committer approvals and prior public discussion (issue or `dev@` thread):
+
+- API or behavior-breaking changes.
+- Architecture or major dependency changes.
+- Security-sensitive changes.
+- Release/build/reproducibility process changes.
+
+## Blocking and Objections
+
+- A blocking objection must include concrete technical reasons and, when possible, a suggested path to resolution.
+- PRs with unresolved blocking objections must not be merged.
+- If consensus is unclear, escalate discussion to `dev@mahout.apache.org`.
+
+## Security and Legal Checks
+
+Before merge, confirm:
+
+- No secrets, credentials, or private data are committed.
+- New dependencies and copied code are license-compatible with Apache-2.0.
+- License/notice updates are included when required (`LICENSE`, `NOTICE`).
+
+## AI-Assisted Contributions
+
+AI-assisted contributions are allowed, including code, documentation, and images, when they comply with ASF legal guidance and normal project review standards.
+
+### Contributor Responsibilities
+
+- The PR author should understand the implementation end-to-end and be able to explain design and code decisions during review.
+- If some generated code is not fully understood, call out the unknowns and assumptions explicitly in the PR for reviewer attention.
+- Avoid submitting "AI dump" PRs (large generated changes without clear understanding, validation, or rationale).
+- PRs that look like unverified AI dumps may be closed or redirected due to limited review capacity.
+
+### Quality Expectations for AI-Assisted PRs
+
+- Add tests and evidence equivalent to non-AI PRs; AI usage does not lower review or quality bars.
+- Keep AI-assisted changes small and reviewable whenever possible.
+- Include reproducible context (problem statement, expected behavior, and constraints), especially for generated fixes.
+
+### Legal and Provenance Requirements
+
+- Contributors remain responsible for ensuring generated output does not introduce incompatible third-party material.
+- The AI tool's terms of use must not conflict with open-source distribution.
+- If third-party material appears in generated output, ensure permission and compatible licensing.
+- Use reasonable checks (tooling, scanners, and manual verification) to reduce copied copyrighted content risk.
+- Recommended practice: disclose AI assistance in commit messages with `Generated-by: <tool-name>`.
+
+When uncertainty remains (for example, unclear provenance, licensing, or design safety), discuss on `dev@mahout.apache.org` before merge.
+
+## Recommended SLA (Non-binding)
+
+- First review response target: within 5 business days.
+- Author follow-up target after requested changes: within 7 business days.
+
+These are goals, not strict requirements.
+
+## References
+
+- ASF Contributor Guide: https://community.apache.org/contributors/
+- ASF Committer Guide: https://community.apache.org/committers/
+- ASF Voting Process: https://www.apache.org/foundation/voting.html
+- ASF License and Contribution FAQs: https://www.apache.org/licenses/
+- ASF Generative Tooling Guidance: https://www.apache.org/legal/generative-tooling.html
+- Apache DataFusion AI-Assisted Contributions: https://datafusion.apache.org/contributor-guide/index.html#ai-assisted-contributions
+- Project contribution guide: [`CONTRIBUTING.md`](https://github.com/apache/mahout/blob/main/CONTRIBUTING.md)
+- CODEOWNERS: [`.github/CODEOWNERS`](https://github.com/apache/mahout/blob/main/.github/CODEOWNERS)

website/sidebars.ts

@@ -94,6 +94,7 @@ const sidebars: SidebarsConfig = {
         'community/who-we-are',
         'community/mailing-lists',
         'community/code-of-conduct',
+        'community/pr-policy-and-review-guidelines',
       ],
     },
     {