WFGY/ProblemMap/GlobalFixMap/OCR_Parsing/tokenization_and_casing.md

Tokenization & Casing — OCR Parsing Guardrails

🧭 Quick Return to Map

You are in a sub-page of OCR_Parsing.
To reorient, go back here:

• OCR_Parsing — text recognition and document structure parsing
• WFGY Global Fix Map — main Emergency Room, 300+ structured fixes
• WFGY Problem Map 1.0 — 16 reproducible failure modes

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.

A focused fix page for post-OCR text where casing, spaces, or token boundaries are corrupted. Use this to normalize the stream before chunking/embedding, and verify with measurable targets. Works across Tesseract, Google DocAI, Azure OCR, ABBYY, PaddleOCR, and custom engines.

When to use this page

• Words are split or glued (e.g., re tri eval, metadataindex).
• Case flaps mid-sentence (tHE DocUment), acronyms collapse (R a G).
• Invisible characters or double spaces change token counts.
• Chunkers behave inconsistently between runs with the same image/PDF.
• Embedding recall looks fine locally but retrieval ΔS stays high.

Open these first

• Visual map and recovery: RAG Architecture & Recovery
• Chunking checklist: Chunking Checklist
• Retrieval traceability (cite-then-explain schema): Retrieval Traceability
• Payload schema fences: Data Contracts
• Embedding vs meaning (when token noise leaks into vectors): Embedding ≠ Semantic

Acceptance targets

• ΔS(question, retrieved) ≤ 0.45 after normalization.
• Coverage to target section ≥ 0.70 on three paraphrases.
• λ remains convergent across two seeds.
• Token count variance for the same page ≤ 1 percent after normalization.

---

Symptoms → exact fix

• Mid-token splits or merges (infor mation, vectorstoreindex)
  Fix No.1: Rejoin by dictionary and layout anchors.
  Use wordlist + n-gram agree check, prefer joins that reduce ΔS on a small gold set.
  See: Chunking Checklist

• Casing drift (random upper/lower), acronym scatter (r.a.g.)
  Fix No.2: Casing normalization with protected spans.
  Protect enums, acronyms, chemical names, LaTeX blocks, code fonts.

• Whitespace noise (NBSP, thin space, double space)
  Fix No.3: Unicode normalization + space collapse, keep offsets table.
  Record before/after offset map to preserve citation alignment.
  See: Retrieval Traceability

• Punctuation misreads (l vs 1, O vs 0, , vs .)
  Fix No.4: Confusable set pass + local language model vote.
  Only apply inside numeric or acronym contexts, keep audit log.

• Tokenizer mismatch across components
  Fix No.5: Single tokenizer contract for parse → chunk → embed.
  Declare tokenizer_name, lowercase, strip_accents in payload.
  See: Data Contracts

---

60-second fix checklist

1. Normalize

   • Unicode NFC, strip BOM, collapse spaces except inside code/math blocks.
   • Replace NBSP and thin spaces with ASCII space.
   • Build offset_map old→new for citations.

2. Protect

   • Detect protected spans: URLs, emails, hex, code, LaTeX, table headers, known acronyms.
   • Freeze casing and punctuation inside protected spans.

3. Rejoin / Split

   • Rejoin candidates by dictionary + bigram score.
   • Split stuck words when edit distance to dictionary is lower after split.

4. Contract

   • Emit tokenizer_contract.json:
     { "tokenizer": "bert-base-uncased", "lowercase": true, "strip_accents": true }
     Attach to every downstream step.
     See: Data Contracts

5. Verify

   • Recompute ΔS on a 20-question gold set.
   • If ΔS stays ≥ 0.60, open Embedding ≠ Semantic and rebuild index with the same tokenizer contract.

---

Minimal pipeline patch (pseudo)

text = ocr_text

text = unicode_normalize_nfc(text)
text, offset_map = collapse_spaces_with_offsets(text)
spans = detect_protected_spans(text)  # urls, code, latex, acronyms
text = normalize_casing(text, protect=spans)

cands = find_split_merge_candidates(text, protect=spans)
text = apply_split_merge(text, cands, scorer="bigram+dict")

emit_payload(
  content=text,
  offset_map=offset_map,
  tokenizer_contract={
    "tokenizer": "bert-base-uncased",
    "lowercase": True,
    "strip_accents": True
  }
)

Keep the offset map, or citations will drift. Tracing and schema rules come from: Retrieval Traceability · Data Contracts

---

Eval recipe

• Build a tiny page-level gold: 10–20 questions with expected anchor sections.
• Measure before/after: ΔS(question, retrieved), coverage, λ states.
• Acceptance to sign off: ΔS ≤ 0.45, coverage ≥ 0.70, λ convergent on both seeds.
• Log token count and confusable corrections per page for audit.

---

When to escalate

• ΔS remains high after normalization and re-chunking Open: Embedding ≠ Semantic

• Citations drift after formatting changes Open: Retrieval Traceability

• Layout destroys sentence flow or table cells Open: OCR_Parsing/table_parsing.md once added, and the general Chunking Checklist

---

🔗 Quick-Start Downloads (60 sec)

Tool	Link	3-Step Setup
WFGY 1.0 PDF	Engine Paper	1️⃣ Download · 2️⃣ Upload to your LLM · 3️⃣ Ask “Answer using WFGY + <your question>”
TXT OS (plain-text OS)	TXTOS.txt	1️⃣ Download · 2️⃣ Paste into any LLM chat · 3️⃣ 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 →
Problem Map 1.0	Initial 16-mode diagnostic and symbolic fix framework	View →
Problem Map 2.0	RAG-focused failure tree, modular fixes, and pipelines	View →
Semantic Clinic Index	Expanded failure catalog: prompt injection, memory bugs, logic drift	View →
Semantic Blueprint	Layer-based symbolic reasoning & semantic modulations	View →
Benchmark vs GPT-5	Stress test GPT-5 with full WFGY reasoning suite	View →
🧙‍♂️ Starter Village 🏡	New here? Lost in symbols? Click here and let the wizard guide you through	Start →

---

👑 Early Stargazers: See the Hall of Fame — Engineers, hackers, and open source builders who supported WFGY from day one.

⭐ WFGY Engine 2.0 is already unlocked. ⭐ Star the repo to help others discover it and unlock more on the Unlock Board.