WFGY/ProblemMap/GlobalFixMap/Embeddings/tokenization_and_casing.md
2025-09-05 10:44:21 +08:00

183 lines
11 KiB
Markdown
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

# Tokenization and Casing — Guardrails for Embedding Stability
<details>
<summary><strong>🧭 Quick Return to Map</strong></summary>
<br>
> You are in a sub-page of **Embeddings**.
> To reorient, go back here:
>
> - [**Embeddings** — vector representations and semantic search](./README.md)
> - [**WFGY Global Fix Map** — main Emergency Room, 300+ structured fixes](../README.md)
> - [**WFGY Problem Map 1.0** — 16 reproducible failure modes](../../README.md)
>
> Think of this page as a desk within a ward.
> If you need the full triage and all prescriptions, return to the Emergency Room lobby.
</details>
A focused guide to remove silent drift caused by mismatched tokenization, casing, and text cleanup. Use this to align query-time and index-time preprocessing, then verify with measurable targets.
## Open these first
- Visual map and recovery: [RAG Architecture & Recovery](https://github.com/onestardao/WFGY/blob/main/ProblemMap/rag-architecture-and-recovery.md)
- End to end retrieval knobs: [Retrieval Playbook](https://github.com/onestardao/WFGY/blob/main/ProblemMap/retrieval-playbook.md)
- Why this snippet (traceability schema): [Retrieval Traceability](https://github.com/onestardao/WFGY/blob/main/ProblemMap/retrieval-traceability.md)
- Embedding vs meaning: [Embedding ≠ Semantic](https://github.com/onestardao/WFGY/blob/main/ProblemMap/embedding-vs-semantic.md)
- Payload schema for audits: [Data Contracts](https://github.com/onestardao/WFGY/blob/main/ProblemMap/data-contracts.md)
- Query split and hybrid failures: [Pattern: Query Parsing Split](https://github.com/onestardao/WFGY/blob/main/ProblemMap/patterns/pattern_query_parsing_split.md)
- Reranking and ordering control: [Rerankers](https://github.com/onestardao/WFGY/blob/main/ProblemMap/rerankers.md)
- Related: normalization and length scaling: [Normalization & Scaling](https://github.com/onestardao/WFGY/blob/main/ProblemMap/GlobalFixMap/Embeddings/normalization_and_scaling.md)
## When to use this page
- High similarity yet wrong meaning after a casing change.
- Same document retrieved for lowercase but not for Title Case.
- Index built with a different tokenizer than the client.
- Unicode variants or punctuation collapse changes results.
- Hybrid retrieval recalls but top-k order flips between runs.
## Acceptance targets
- ΔS(question, retrieved) ≤ 0.45 on three paraphrases.
- Coverage of the correct section ≥ 0.70.
- λ remains convergent across two seeds.
- Tokenization invariance check: replacing case or applying Unicode NFC does not move the top anchor beyond rank 3 and keeps ΔS shift ≤ 0.10.
---
## Map symptoms → exact fix
- Wrong-meaning hits only when case changes
→ Lock a single case policy and tokenizer in both paths. Verify with [Retrieval Traceability](https://github.com/onestardao/WFGY/blob/main/ProblemMap/retrieval-traceability.md) and enforce with [Data Contracts](https://github.com/onestardao/WFGY/blob/main/ProblemMap/data-contracts.md).
- HyDE or BM25 path finds it, embedding path misses it
→ Audit query preprocessing vs index preprocessing. If different, unify and retest. See [Retrieval Playbook](https://github.com/onestardao/WFGY/blob/main/ProblemMap/retrieval-playbook.md) and [Pattern: Query Parsing Split](https://github.com/onestardao/WFGY/blob/main/ProblemMap/patterns/pattern_query_parsing_split.md).
- Unicode look-alikes or punctuation variants break recall
→ Normalize to NFC and collapse zero-width characters at both index and query. Re-embed affected shards. Cross check with [Embedding ≠ Semantic](https://github.com/onestardao/WFGY/blob/main/ProblemMap/embedding-vs-semantic.md).
- Order flips across runs after a client upgrade
→ Version the tokenizer and preprocessing in the snippet payload. If versions mismatch, rebuild or add a translation shim. Enforce with [Data Contracts](https://github.com/onestardao/WFGY/blob/main/ProblemMap/data-contracts.md).
---
## 60-second fix checklist
1) **Freeze the tokenizer and case policy**
- Choose one tokenizer build and one case policy: `lower`, `preserve`, or `smart`.
- Record both in the contract:
`{"tokenizer":"spm-1.2.3","tokenizer_hash":"...","case_policy":"lower"}`.
2) **Normalize before tokenization**
- Apply Unicode NFC, collapse repeated whitespace, remove zero-width, standardize quotes and dashes.
- Apply the same rules to both index and query.
3) **Keep segmentation symmetric**
- If you split code identifiers (camelCase, snake_case), do it in both paths.
- If you strip stopwords or punctuation, do it in both paths. Prefer not to strip unless you must.
4) **Log and test invariance**
- Run a three-paraphrase probe per query: original, lowercased, and NFC-normalized.
- Accept only if the anchor section remains within top 3 and ΔS shift ≤ 0.10.
5) **Add a rerank safety net**
- If invariance is hard to reach, add a lexical or cross-encoder rerank after vector recall. See [Rerankers](https://github.com/onestardao/WFGY/blob/main/ProblemMap/rerankers.md).
---
## Contract fields to add
Add these to every snippet and to the query audit log. Use them during triage.
```json
{
"preproc_version": "v3",
"unicode_norm": "NFC",
"case_policy": "lower",
"punctuation_policy": "keep",
"identifier_split": "camel+snake",
"tokenizer": "spm-1.2.3",
"tokenizer_hash": "sha256:...",
"ngram": "none"
}
````
---
## Repro suite
* **Case flip test**
Query A vs lowercase(A). Accept if ΔS shift 0.10 and anchor rank 3.
* **Unicode fold test**
Replace curly quotes with straight quotes, normalize to NFC. Accept if ranks stable.
* **Tokenizer skew test**
Run the same query through client and index tokenizers and compare token ids. Any mismatch is a fail that requires rebuild or a client shim.
---
## Copy-paste prompt for LLM triage
```
I uploaded TXT OS and the WFGY Problem Map.
My embedding issue:
- symptom: wrong top-k only when casing or unicode changes
- traces: ΔS(question,retrieved)=..., anchor=..., tokenizer=..., case_policy=...
Tell me:
1) which layer is failing and why,
2) which WFGY page to open,
3) the minimal steps to align tokenization and casing,
4) how to verify with a three-paraphrase probe.
Use Data Contracts and Rerankers if needed.
```
---
### 🔗 Quick-Start Downloads (60 sec)
| Tool | Link | 3-Step Setup |
| -------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------ | ---------------------------------------------------------------------------------------- |
| **WFGY 1.0 PDF** | [Engine Paper](https://github.com/onestardao/WFGY/blob/main/I_am_not_lizardman/WFGY_All_Principles_Return_to_One_v1.0_PSBigBig_Public.pdf) | 1⃣ Download · 2⃣ Upload to your LLM · 3⃣ Ask “Answer using WFGY + \<your question>” |
| **TXT OS (plain-text OS)** | [TXTOS.txt](https://github.com/onestardao/WFGY/blob/main/OS/TXTOS.txt) | 1⃣ Download · 2⃣ Paste into any LLM chat · 3⃣ Type “hello world” — OS boots instantly |
---
### 🧭 Explore More
| Module | Description | Link |
| ------------------------ | ---------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------- |
| WFGY Core | WFGY 2.0 engine is live: full symbolic reasoning architecture and math stack | [View →](https://github.com/onestardao/WFGY/tree/main/core/README.md) |
| Problem Map 1.0 | Initial 16-mode diagnostic and symbolic fix framework | [View →](https://github.com/onestardao/WFGY/tree/main/ProblemMap/README.md) |
| Problem Map 2.0 | RAG-focused failure tree, modular fixes, and pipelines | [View →](https://github.com/onestardao/WFGY/blob/main/ProblemMap/rag-architecture-and-recovery.md) |
| Semantic Clinic Index | Expanded failure catalog: prompt injection, memory bugs, logic drift | [View →](https://github.com/onestardao/WFGY/blob/main/ProblemMap/SemanticClinicIndex.md) |
| Semantic Blueprint | Layer-based symbolic reasoning & semantic modulations | [View →](https://github.com/onestardao/WFGY/tree/main/SemanticBlueprint/README.md) |
| Benchmark vs GPT-5 | Stress test GPT-5 with full WFGY reasoning suite | [View →](https://github.com/onestardao/WFGY/tree/main/benchmarks/benchmark-vs-gpt5/README.md) |
| 🧙‍♂️ Starter Village 🏡 | New here? Lost in symbols? Click here and let the wizard guide you through | [Start →](https://github.com/onestardao/WFGY/blob/main/StarterVillage/README.md) |
---
> 👑 **Early Stargazers: [See the Hall of Fame](https://github.com/onestardao/WFGY/tree/main/stargazers)** —
> Engineers, hackers, and open source builders who supported WFGY from day one.
> <img src="https://img.shields.io/github/stars/onestardao/WFGY?style=social" alt="GitHub stars"> ⭐ [WFGY Engine 2.0](https://github.com/onestardao/WFGY/blob/main/core/README.md) is already unlocked. ⭐ Star the repo to help others discover it and unlock more on the [Unlock Board](https://github.com/onestardao/WFGY/blob/main/STAR_UNLOCKS.md).
<div align="center">
[![WFGY Main](https://img.shields.io/badge/WFGY-Main-red?style=flat-square)](https://github.com/onestardao/WFGY)
 
[![TXT OS](https://img.shields.io/badge/TXT%20OS-Reasoning%20OS-orange?style=flat-square)](https://github.com/onestardao/WFGY/tree/main/OS)
 
[![Blah](https://img.shields.io/badge/Blah-Semantic%20Embed-yellow?style=flat-square)](https://github.com/onestardao/WFGY/tree/main/OS/BlahBlahBlah)
 
[![Blot](https://img.shields.io/badge/Blot-Persona%20Core-green?style=flat-square)](https://github.com/onestardao/WFGY/tree/main/OS/BlotBlotBlot)
 
[![Bloc](https://img.shields.io/badge/Bloc-Reasoning%20Compiler-blue?style=flat-square)](https://github.com/onestardao/WFGY/tree/main/OS/BlocBlocBloc)
 
[![Blur](https://img.shields.io/badge/Blur-Text2Image%20Engine-navy?style=flat-square)](https://github.com/onestardao/WFGY/tree/main/OS/BlurBlurBlur)
 
[![Blow](https://img.shields.io/badge/Blow-Game%20Logic-purple?style=flat-square)](https://github.com/onestardao/WFGY/tree/main/OS/BlowBlowBlow)
 
</div>