# Rule 47: Disambiguation Entity Profiles - Prevent Repeated Entity Resolution Errors

## Status: CRITICAL

## Summary

When entity resolution determines that a web source describes a **different person** with a similar name, **create a PPID profile for that person** in `data/person/`. The PPID system is universal - ANY person who ever lived can have a profile, regardless of heritage relevance.

---

## The Universal PPID Principle

**In principle, all persons on Earth should be assigned PPIDs** - whether or not they are active in the heritage field. This includes:

- Heritage workers (curators, archivists, librarians, etc.)
- Non-heritage professionals (actors, doctors, athletes, etc.)
- Historical persons (deceased individuals from any era)
- Public figures and private individuals

The `heritage_relevance` field indicates whether someone works in the heritage sector, but does NOT determine whether they can have a profile. **Anyone can have a PPID.**

---

## The Problem

During entity resolution, we often discover that web search results describe a **different person** with a similar name:

| Heritage Profile | Namesake Discovered | Why Different |
|------------------|---------------------|---------------|
| Carmen Juliá (UK curator) | Carmen Julia Álvarez (Venezuelan actress) | Different profession, location, timeline |
| Jan de Vries (Rijksmuseum curator) | Jan de Vries (footballer) | Different profession |
| Robert Ritter (heritage worker) | Robert Ritter (Nazi doctor, 1901-1951) | Different era, profession |

Without creating a profile for the namesake, future enrichment attempts may:
1. Re-discover the same namesake
2. Waste time re-investigating
3. Risk attributing false claims again

---

## The Solution: Create PPID Profiles for Namesakes

When entity resolution proves two entities are different, **create a regular PPID profile for the namesake**:

1. Use standard PPID naming convention (no special prefix)
2. Set `heritage_relevance.is_heritage_relevant: false`
3. Document the disambiguation in BOTH profiles

---

## Example: Venezuelan Actress Profile

```json
{
  "ppid": "ID_VE-XX-CCS_1952_VE-XX-CCS_XXXX_CARMEN-JULIA-ALVAREZ",
  "profile_data": {
    "full_name": "Carmen Julia Álvarez",
    "profession": "actress",
    "nationality": "Venezuelan",
    "birth_year": 1952,
    "birth_location": "Caracas, Venezuela",
    "active_period": "1970s-2000s"
  },
  "heritage_relevance": {
    "is_heritage_relevant": false,
    "relevance_score": 0.0,
    "reason": "Entertainment industry professional - actress in film and television"
  },
  "disambiguation_notes": {
    "commonly_confused_with": [
      {
        "ppid": "ID_UK-XX-XXX_XXXX_UK-XX-XXX_XXXX_CARMEN-JULIA",
        "name": "Carmen Juliá",
        "profession": "curator",
        "employer": "New Contemporaries",
        "location": "UK",
        "why_different": "Different profession (actress vs curator), different location (Venezuela vs UK), overlapping active periods in incompatible roles"
      }
    ],
    "disambiguation_note": "This is the Venezuelan actress, NOT the UK-based art curator."
  },
  "web_claims": [
    {
      "claim_type": "birth_year",
      "claim_value": 1952,
      "provenance": {
        "source_url": "https://en.wikipedia.org/wiki/Carmen_Julia_Álvarez",
        "retrieved_on": "2026-01-11T14:30:00Z",
        "retrieval_agent": "manual-human-curator"
      }
    },
    {
      "claim_type": "profession",
      "claim_value": "actress",
      "provenance": {
        "source_url": "https://en.wikipedia.org/wiki/Carmen_Julia_Álvarez",
        "retrieved_on": "2026-01-11T14:30:00Z",
        "retrieval_agent": "manual-human-curator"
      }
    }
  ],
  "extraction_metadata": {
    "created_at": "2026-01-11T15:00:00Z",
    "created_by": "manual-human-curator",
    "creation_reason": "Created during entity resolution to distinguish from heritage worker Carmen Juliá"
  }
}
```

---

## Update the Heritage Profile Too

The heritage profile should also reference the disambiguation:

```json
{
  "ppid": "ID_UK-XX-XXX_XXXX_UK-XX-XXX_XXXX_CARMEN-JULIA",
  "profile_data": {
    "full_name": "Carmen Juliá",
    "headline": "Curator at New Contemporaries"
  },
  "heritage_relevance": {
    "is_heritage_relevant": true,
    "relevance_score": 0.85
  },
  "disambiguation_notes": {
    "known_namesakes": [
      {
        "ppid": "ID_VE-XX-CCS_1952_VE-XX-CCS_XXXX_CARMEN-JULIA-ALVAREZ",
        "name": "Carmen Julia Álvarez",
        "profession": "actress",
        "location": "Venezuela",
        "why_not_same_person": "Different profession, location, timeline"
      }
    ],
    "disambiguation_warning": "Web searches for 'Carmen Julia' return data about Venezuelan actress Carmen Julia Álvarez (born 1952). This is a DIFFERENT person."
  }
}
```

---

## When to Create Namesake Profiles

Create a PPID profile for a namesake when:

1. **Entity resolution proves they are a different person**
2. **They are notable enough** to appear in search results repeatedly (Wikipedia, IMDB, news)
3. **The confusion risk is high** (similar name, some overlapping attributes)

**Do NOT create profiles for**:
- Random social media accounts with no notable presence
- Obvious mismatches unlikely to recur in searches

---

## Benefits

1. **Universal person database**: Any person can have a PPID
2. **Prevents repeated mistakes**: Future enrichment can check for known namesakes
3. **Bidirectional linking**: Both profiles reference each other
4. **Consistent data model**: No special file naming or profile types needed
5. **Audit trail**: Documents why profiles were created

---

## Workflow

### Step 1: During Entity Resolution

When you reject a claim due to identity mismatch with a notable namesake:

```
1. Document WHY the source describes a different person
2. Check if the namesake is notable (Wikipedia, IMDB, frequent search results)
3. If notable → Create PPID profile for the namesake
4. Link both profiles via disambiguation_notes
```

### Step 2: Create Namesake Profile

Use standard PPID naming:
```
ID_{birth-location}_{birth-decade}_{current-location}_{death-decade}_{NAME}.json
```

Example: `ID_VE-XX-CCS_1952_VE-XX-CCS_XXXX_CARMEN-JULIA-ALVAREZ.json`

### Step 3: Update Both Profiles

- Namesake profile: Add `commonly_confused_with` pointing to heritage profile
- Heritage profile: Add `known_namesakes` pointing to namesake profile

---

## Historical Persons

Historical persons (deceased) can also have PPID profiles:

```json
{
  "ppid": "ID_DE-XX-XXX_1901_DE-XX-XXX_1951_ROBERT-RITTER",
  "profile_data": {
    "full_name": "Robert Ritter",
    "profession": "physician",
    "birth_year": 1901,
    "death_year": 1951,
    "nationality": "German",
    "historical_note": "Nazi-era physician involved in racial hygiene programs"
  },
  "heritage_relevance": {
    "is_heritage_relevant": false,
    "relevance_score": 0.0
  },
  "disambiguation_notes": {
    "commonly_confused_with": [
      {
        "ppid": "ID_XX-XX-XXX_XXXX_XX-XX-XXX_XXXX_ROBERT-RITTER",
        "name": "Robert Ritter",
        "profession": "heritage worker",
        "why_different": "Different era - historical figure (1901-1951) vs living heritage professional"
      }
    ]
  }
}
```

---

## Related Rules

- **Rule 46**: Entity Resolution - Names Are NEVER Sufficient
- **Rule 21**: Data Fabrication is Strictly Prohibited
- **Rule 26**: Person Data Provenance - Web Claims for Staff Information

---

## Summary

**The PPID system is universal.** When you discover during entity resolution that a web source describes a different person:

1. **Create a regular PPID profile** for the namesake (actress, historical figure, etc.)
2. **Set `heritage_relevance.is_heritage_relevant: false`** (unless they happen to also work in heritage)
3. **Link both profiles** via `disambiguation_notes`
4. **Use standard PPID naming** - no special prefixes needed

This builds a comprehensive person database while preventing entity resolution errors.