# Rule 46: Entity Resolution in Person Enrichment - No Heuristics

## Status: CRITICAL

## The Core Principle

🚨 **SIMILAR OR IDENTICAL NAMES ARE NEVER SUFFICIENT FOR ENTITY RESOLUTION.**

A web search result mentioning "Carmen Juliá born 1952" is **NOT** evidence that the Carmen Juliá in our person profile was born in 1952. Names are not unique identifiers - there are thousands of people with the same name worldwide.

**Entity resolution requires verification of MULTIPLE independent identity attributes:**

| Attribute | Purpose | Example |
|-----------|---------|---------|
| **Age/Birth Year** | Temporal consistency | Both sources describe someone in their 40s |
| **Career Path** | Professional identity | Both are art curators, not one curator and one actress |
| **Location** | Geographic consistency | Both are based in UK, not one UK and one Venezuela |
| **Employer** | Institutional affiliation | Both work at New Contemporaries |
| **Education** | Academic background | Same university or field |

**Minimum Requirement**: At least **3 of 5** attributes must match before attributing ANY claim from a web source. Name match alone = **AUTOMATIC REJECTION**.

## Problem Statement

When enriching person profiles via web search (Linkup, Exa, etc.), search results often return data about **different people with similar or identical names**. Without proper entity resolution, the enrichment process can attribute false claims to the wrong person.

**Example Failure** (Carmen Juliá - UK Art Curator):
- Source profile: Carmen Juliá, Curator at New Contemporaries (UK)
- Birth year extracted: 1952 from Carmen Julia **Álvarez** (Venezuelan actress)
- Spouse extracted: "actors Eduardo Serrano" from the Venezuelan actress
- ResearchGate: Carmen Julia **Navarro** (Mexican hydrogeologist)
- Academia.edu: Carmen Julia **Gutiérrez** (Spanish medieval studies)

All data is from **different people** - none is the actual Carmen Juliá who is a UK-based art curator.

**Why This Happened**: The enrichment script used regex pattern matching to extract "born 1952" without verifying that the Wikipedia article described the SAME person.

## The Rule

### DO NOT use name matching as the basis for entity resolution. EVER.

For person enrichment via web search:

**FORBIDDEN** (Name-based extraction):
- ❌ Extracting birth years from any search result mentioning "Carmen Julia born..." 
- ❌ Attributing social media profiles just because the name appears
- ❌ Claiming relationships (spouse, parent, child) from web text pattern matching
- ❌ Assigning academic profiles (ResearchGate, Academia.edu, Google Scholar) based on name matching alone
- ❌ Using Wikipedia articles without verifying ALL identity attributes
- ❌ Trusting genealogy sites (Geni, Ancestry, MyHeritage) which describe historical namesakes
- ❌ Using IMDB for birth years (actors with same names)

**REQUIRED** (Multi-Attribute Entity Resolution):
1. **Verify identity via MULTIPLE attributes** - name alone is INSUFFICIENT
2. **Cross-reference with known facts** (employer, location, job title from LinkedIn)
3. **Detect conflicting signals** - actress vs curator, Venezuela vs UK, 1950s birth vs active 2020s career
4. **Reject ambiguous matches** - if source doesn't clearly identify the same person, reject the claim
5. **Document rejection rationale** - log why claim was rejected for audit trail

## Entity Resolution Verification Checklist

Before attributing a web claim to a person profile, verify MULTIPLE identity attributes:

| # | Attribute | What to Check | Example Match | Example Conflict |
|---|-----------|---------------|---------------|------------------|
| 1 | **Career/Profession** | Same field/industry | Both are curators | Source says "actress", profile is curator |
| 2 | **Employer** | Same institution | Both at Rijksmuseum | Source says "film studio", profile is museum |
| 3 | **Location** | Same city/country | Both UK-based | Source says Venezuela, profile is UK |
| 4 | **Age Range** | Plausible for career | Birth 1980s, active 2020s | Birth 1952, still active in 2025 as junior |
| 5 | **Education** | Same university/field | Both art history | Source says "medical school" |

**Minimum requirement**: At least **3 of 5** attributes must match. Name match alone = **AUTOMATIC REJECTION**.

**Any conflicting signal = AUTOMATIC REJECTION** (e.g., source says "actress" when profile is "curator").

## Sources with High Entity Resolution Risk

| Source Type | Risk Level | Why | Action |
|-------------|------------|-----|--------|
| Wikipedia | CRITICAL | Many people with same name have pages | Reject unless 4/5 attributes match |
| IMDB | CRITICAL | Actors with common names | Reject all - never use for birth years |
| Genealogy sites | CRITICAL | Historical persons with same name | **ALWAYS REJECT** - these are ancestors/namesakes |
| Academic profiles | HIGH | Multiple researchers with same name | Verify institution and research field match |
| Social media | HIGH | Many accounts with similar handles | Verify employer/location in bio |
| News articles | MEDIUM | May mention multiple people | Read full context, verify identity |
| Institutional websites | LOW | Usually about their own staff | Good source if person works there |

## Automatic Rejection Triggers

The following MUST trigger **automatic claim rejection**:

### Profession Conflicts
If source profession differs from profile profession, REJECT:
```
Source: "actress", "actor", "singer", "footballer", "politician"
Profile: "curator", "archivist", "librarian", "conservator", "registrar"
→ REJECT (these are different people)
```

### Location Conflicts
If source location conflicts with profile location, REJECT:
```
Source: "Venezuela", "Mexico", "Brazil"
Profile: "UK", "Netherlands", "France"
→ REJECT (these are different people)
```

### Age Conflicts
If source age is implausible for profile career stage, REJECT:
```
Source: Born 1922, 1915, 1939
Profile: Currently active professional in 2025
→ REJECT (person would be 86-103 years old)

Source: Born 2007, 2004
Profile: Senior curator
→ REJECT (person would be 18-21, too young)
```

### Genealogy Source
If source is from genealogy/ancestry site, ALWAYS REJECT:
```
Domains: geni.com, ancestry.*, familysearch.org, findagrave.com, myheritage.*
→ ALWAYS REJECT (these describe historical namesakes, not the living person)
```

## Implementation in Enrichment Scripts

```python
def validate_entity_match(profile: dict, search_result: dict) -> tuple[bool, str]:
    """
    Validate that a search result refers to the same person as the profile.
    
    REQUIRES: At least 3 of 5 identity attributes must match.
    Name match alone is INSUFFICIENT and automatically rejected.
    
    Returns (is_valid, reason)
    """
    profile_employer = profile.get('affiliations', [{}])[0].get('custodian_name', '').lower()
    profile_location = profile.get('profile_data', {}).get('location', '').lower()
    profile_role = profile.get('profile_data', {}).get('headline', '').lower()
    
    source_text = search_result.get('answer', '').lower()
    source_url = search_result.get('source_url', '').lower()
    
    # AUTOMATIC REJECTION: Genealogy sources
    genealogy_domains = ['geni.com', 'ancestry.', 'familysearch.', 'findagrave.', 'myheritage.']
    if any(domain in source_url for domain in genealogy_domains):
        return False, "genealogy_source_rejected"
    
    # AUTOMATIC REJECTION: Profession conflicts
    heritage_roles = ['curator', 'archivist', 'librarian', 'conservator', 'registrar', 'collection', 'heritage']
    entertainment_roles = ['actress', 'actor', 'singer', 'footballer', 'politician', 'model', 'athlete']
    
    profile_is_heritage = any(role in profile_role for role in heritage_roles)
    source_is_entertainment = any(role in source_text for role in entertainment_roles)
    
    if profile_is_heritage and source_is_entertainment:
        return False, "conflicting_profession"
    
    # AUTOMATIC REJECTION: Location conflicts
    if profile_location:
        location_conflicts = [
            ('venezuela', 'uk'), ('mexico', 'netherlands'), ('brazil', 'france'),
            ('caracas', 'london'), ('mexico city', 'amsterdam')
        ]
        for source_loc, profile_loc in location_conflicts:
            if source_loc in source_text and profile_loc in profile_location:
                return False, "conflicting_location"
    
    # Count positive identity attribute matches (need 3 of 5)
    matches = 0
    match_details = []
    
    # 1. Employer match
    if profile_employer and profile_employer in source_text:
        matches += 1
        match_details.append(f"employer:{profile_employer}")
    
    # 2. Location match
    if profile_location and profile_location in source_text:
        matches += 1
        match_details.append(f"location:{profile_location}")
    
    # 3. Role/profession match
    if profile_role:
        role_words = [w for w in profile_role.split() if len(w) > 4]
        if any(word in source_text for word in role_words):
            matches += 1
            match_details.append(f"role_match")
    
    # 4. Education/institution match (if available)
    profile_education = profile.get('profile_data', {}).get('education', [])
    if profile_education:
        edu_names = [e.get('school', '').lower() for e in profile_education if e.get('school')]
        if any(edu in source_text for edu in edu_names):
            matches += 1
            match_details.append(f"education_match")
    
    # 5. Time period match (career dates)
    # (implementation depends on available data)
    
    # REQUIRE 3 OF 5 MATCHES
    if matches < 3:
        return False, f"insufficient_identity_verification (only {matches}/5 attributes matched)"
    
    return True, f"verified ({matches}/5 matches: {', '.join(match_details)})"
```

## Claim Rejection Patterns

The following patterns should trigger automatic claim rejection:

```python
# Genealogy sources - ALWAYS REJECT
GENEALOGY_DOMAINS = [
    'geni.com', 'ancestry.com', 'ancestry.co.uk', 'familysearch.org',
    'findagrave.com', 'myheritage.com', 'wikitree.com', 'geneanet.org'
]

# Profession conflicts - if profile has one and source has another, REJECT
PROFESSION_CONFLICTS = {
    'heritage': ['curator', 'archivist', 'librarian', 'conservator', 'registrar', 'collection manager'],
    'entertainment': ['actress', 'actor', 'singer', 'footballer', 'politician', 'model', 'athlete'],
    'medical': ['doctor', 'nurse', 'surgeon', 'physician'],
    'tech': ['software engineer', 'developer', 'programmer'],
}

# Location conflicts - if source describes person in location X and profile is location Y, REJECT
LOCATION_PAIRS = [
    ('venezuela', 'uk'), ('venezuela', 'netherlands'), ('venezuela', 'germany'),
    ('mexico', 'uk'), ('mexico', 'netherlands'), ('brazil', 'france'),
    ('caracas', 'london'), ('caracas', 'amsterdam'),
]

# Age impossibility - if birth year makes current career implausible, REJECT
MIN_PLAUSIBLE_BIRTH_YEAR = 1945  # Would be 80 in 2025 - still plausible but verify
MAX_PLAUSIBLE_BIRTH_YEAR = 2002  # Would be 23 in 2025 - plausible for junior roles
```

## Handling Rejected Claims

When a claim fails entity resolution:

```json
{
  "claim_type": "birth_year",
  "claim_value": 1952,
  "entity_resolution": {
    "status": "REJECTED",
    "reason": "conflicting_profession",
    "details": "Source describes Venezuelan actress, profile is UK curator",
    "source_identity": "Carmen Julia Álvarez (Venezuelan actress)",
    "profile_identity": "Carmen Juliá (UK art curator)",
    "rejected_at": "2026-01-11T15:00:00Z",
    "rejected_by": "entity_resolution_validator_v1"
  }
}
```

## Special Cases

### Common Names

For very common names (e.g., "John Smith", "Maria García", "Jan de Vries"), require **4 of 5** verification checks instead of 3. The more common the name, the higher the threshold.

| Name Commonality | Required Matches |
|------------------|------------------|
| Unique name (e.g., "Xander Vermeulen-Oosterhuis") | 2 of 5 |
| Moderately common (e.g., "Carmen Juliá") | 3 of 5 |
| Very common (e.g., "Jan de Vries") | 4 of 5 |
| Extremely common (e.g., "John Smith") | 5 of 5 or reject |

### Abbreviated Names

For profiles with abbreviated names (e.g., "J. Smith"), entity resolution is inherently uncertain:
- Set `entity_resolution_confidence: "very_low"`
- Require **human review** for all claims
- Do NOT attribute web claims automatically

### Historical Persons

When sources describe historical/deceased persons:
- Check if death date conflicts with profile activity (living person active in 2025)
- **ALWAYS REJECT** genealogy site data
- Reject any source describing events before 1950 unless profile is known to be historical

### Wikipedia Articles

Wikipedia is particularly dangerous because:
- Many people with the same name have articles
- Search engines return Wikipedia first
- The Wikipedia Carmen Julia Álvarez article describes a Venezuelan actress born 1952
- This is a DIFFERENT PERSON from Carmen Juliá the UK curator

**For Wikipedia sources**:
1. Read the FULL article, not just snippets
2. Verify the Wikipedia subject's profession matches the profile
3. Verify the Wikipedia subject's location matches the profile
4. If ANY conflict detected → REJECT

## Audit Trail

All entity resolution decisions must be logged:

```json
{
  "enrichment_history": [
    {
      "enrichment_timestamp": "2026-01-11T15:00:00Z",
      "enrichment_agent": "enrich_person_comprehensive.py v1.4.0",
      "entity_resolution_decisions": [
        {
          "source_url": "https://en.wikipedia.org/wiki/Carmen_Julia_Álvarez",
          "decision": "REJECTED",
          "reason": "Different person - Venezuelan actress, not UK curator"
        }
      ],
      "claims_rejected_count": 5,
      "claims_accepted_count": 1
    }
  ]
}
```

## See Also

- Rule 21: Data Fabrication is Strictly Prohibited
- Rule 26: Person Data Provenance - Web Claims for Staff Information
- Rule 45: Inferred Data Must Be Explicit with Provenance