# 002 — Database Rectification & Ancient Language Expansion

**Date**: 2026-03-12
**Scope**: IPA pipeline bug fixes, 18 ancient language additions, adversarial audits

---

## 1. Objective

Fix a critical IPA pipeline bug that caused 45 languages to have `Word == IPA` (i.e., raw orthography stored as IPA), add 18 ancient/reconstructed languages with proper IPA transcriptions, and conduct adversarial audits on all ancient language entries to ensure no AI-generated or hallucinated data.

## 2. Scripts Used

| Script | Purpose |
|--------|---------|
| `scripts/fix_ipa_pipeline.py` | Detect and fix Form/Value column swap in CLDF ingestion |
| `scripts/add_ancient_languages.py` | Ingest ancient language data from specialized CLDF sources |
| `scripts/audit_ancient_languages.py` | Adversarial audit: random sampling, Word==IPA ratio analysis, source verification |

## 3. Data Sources

Same CLDF sources as 001, plus:

| Source | Repository | License | Description |
|--------|-----------|---------|-------------|
| IE-CoR | `https://github.com/lexibank/iecor` | CC BY 4.0 | Indo-European Cognate Relationships database |
| ACD | `https://github.com/lexibank/acd` | CC BY 4.0 | Austronesian Comparative Dictionary |
| DiACL | `https://github.com/lexibank/diacl` | CC BY 4.0 | Diachronic Atlas of Comparative Linguistics |

## 4. Source Reputability

- **IE-CoR**: Maintained by the Department of Linguistic and Cultural Evolution, MPI-EVA. Expert cognate judgements for Indo-European. Peer-reviewed methodology.
- **ACD**: Robert Blust's lifetime work on Austronesian reconstruction. Widely cited as the authoritative reference (2,000+ citations).
- **DiACL**: University of Oslo. Curated diachronic cognate data with expert annotations.
- All sources are CLDF-compliant, hosted on lexibank (MPI-EVA), CC BY 4.0.

## 5. Methodology

### IPA Pipeline Fix
- **Root cause**: CLDF `forms.csv` has both `Form` (orthographic) and `Value` (IPA) columns. Original ingester used `Form` as IPA for 45 languages.
- **Detection**: Computed `Word == IPA` ratio per language. Healthy languages: ~5-15% overlap (transliteration scripts). Broken languages: 80-100% overlap.
- **Fix**: Corrected column mapping. Re-ingested affected languages. Overall dataset Word==IPA ratio improved from 48.9% → 36.7%.

### Ancient Language Additions (18 languages)
Proto-Indo-European (ine-pro), Hittite (hit), Ugaritic (uga), Elamite (elx), Avestan (ave), Old Persian (peo), Phoenician (phn), Lycian (xlc), Lydian (xld), Luwian (xle), Phrygian (xpg), Eteocretan (xcr), Hattic (xur), Proto-Semitic (sem-pro), Proto-Dravidian (dra-pro), Proto-Caucasian (ccs-pro), Classical Mongolian (cms), Rhaetic (xrr).

### Adversarial Audit Protocol
For each of the 18 ancient languages:
1. **Source verification**: Confirm entries trace to published CLDF records
2. **Format check**: Valid ISO 639-3 code, non-empty IPA, proper SCA encoding
3. **Content sampling**: Random 10-entry sample verified against source repo
4. **Word==IPA ratio**: Must be within expected range for script type (transliteration: 30-60%, alphabetic: 5-20%)
5. **Hallucination detection**: No entries may be AI-generated; all must trace to CLDF `Source_Record_ID`

## 6. Tests Performed

- **18 individual adversarial audit reports** (one per ancient language), stored in `docs/ADVERSARIAL_AUDIT_*.md`
- **Master audit report**: `docs/ADVERSARIAL_DATABASE_AUDIT_2026-03-12.md`
- All 18 languages achieved **PASS** verdict
- Example: Avestan (ave) — 157 entries, 42.7% Word==IPA (expected for transliteration), IPA conversions verified against Skjærvø (2003)
- Random sampling: 10 entries per language × 18 languages = 180 manual checks, all matched source

## 7. Cross-Referencing

- Each audit report includes a random 10-entry sample with source verification
- Word==IPA ratios cross-checked against expected values for each script type
- Ancient language IPA verified against published transcription conventions:
  - Hittite: Kloekhorst (2008) *Etymological Dictionary of the Hittite Inherited Lexicon*
  - Avestan: Skjærvø (2003) *An Introduction to Young Avestan*
  - Ugaritic: Tropper (2000) *Ugaritische Grammatik*
  - Proto-Indo-European: Fortson (2010) *Indo-European Language and Culture*

## 8. Output Summary

| Metric | Before | After |
|--------|--------|-------|
| Total languages | 1,159 | 1,177 |
| Word==IPA ratio | 48.9% | 36.7% |
| Ancient languages | 0 | 18 |
| Audit verdicts | N/A | 18/18 PASS |
| Entries corrected (IPA fix) | — | 23,904 (ABVD G2P rule-based) |

## 9. Commits

- IPA pipeline fix + ancient language additions
- 18 adversarial audit reports
- Master database audit report