# Quality Control (QC) — EV Patent Dataset v1.0

**Build date:** 2025-11-16  
**Coverage:** 2015–2025, USPTO publications (grants + applications)  
**Records:** 576,674 raw → 547,522 cleaned (after deduplication)  
**Output:** Parquet (analytics) + JSONL (sample texts)

---

## Dataset Overview

### Files & Structure
- **Granted Patents:** 130 monthly Parquet files (2015-01 through 2025-10)
- **Applications:** 130 monthly Parquet files (2015-01 through 2025-10)
- **Total Files:** 260 data files
- **Format:** Apache Parquet (optimized for analytics)
- **Supplementary:** Sample text extraction in JSONL.gz format

### Record Counts
- **Total Records (raw):** 576,674
  - Granted Patents: 256,857 (44.5%)
  - Applications: 319,817 (55.5%)
- **Unique Records (post-deduplication):** 547,522
- **Duplicates Removed:** 29,152

### Temporal Coverage
- **Year Range:** 2015–2025
- **Peak Year:** 2023 (74,484 records)
- **Current Year (2025):** 50,420 records (through October)

### Records by Year
| Year | Count   | Year | Count   |
|------|---------|------|---------|
| 2015 | 38,067  | 2021 | 50,818  |
| 2016 | 40,465  | 2022 | 54,161  |
| 2017 | 44,240  | 2023 | 74,484  |
| 2018 | 47,179  | 2024 | 65,425  |
| 2019 | 56,236  | 2025 | 50,420  |
| 2020 | 55,179  |      |         |

---

## Completeness (Key Fields)

| Field | Completeness | Notes |
|-------|--------------|-------|
| **title** | **99.99%** | 576,674 / 576,674 records |
| **abstract** | **99.8%** | 575,657 / 576,674 records |
| **CPC** | **99.8%** | 575,539 / 576,674 records (at least 1 CPC per record) |
| **publication_number** | **100.0%** | 576,674 / 576,674 records |
| **pub_date** | **100.0%** | 576,674 / 576,674 records |
| **assignee** | **64.0%** | 369,300 / 576,674 records |
| **inventors** | **100.0%** | 576,674 / 576,674 records |

> **Note on Assignee Coverage:** 64.0% completeness for assignee field reflects the nature of USPTO data where not all patents have assigned corporate entities (some remain with individual inventors, universities, or governmental bodies).

---

## Deduplication

### Methodology
- **Rule:** Removed duplicates based on `publication_id_full` (canonical identifier: country + doc_number + kind)
- **Duplicates Found:** 29,152 records (5.1% of raw data)
- **Action:** Kept first occurrence per unique publication ID
- **Result:** 547,522 unique records retained

### Duplicate Analysis
Duplicates were exact matches on:
- `publication_id_full` (e.g., US08997261B2)
- `doc_type` (grant/application)
- `pub_date` (publication date)

**Sample Duplicates Identified:**
```
US08997261B2 (grant, 2015-03-31) - 2 instances
US09295186B2 (grant, 2016-03-22) - 2 instances
US09357686B2 (grant, 2016-05-31) - 2 instances
```

---

## Integrity & Reproducibility

### Pipeline
```
Source Downloads → XML Parsing → CPC Filtering → Keyword Matching → 
Normalization → Deduplication → QC Checks → Parquet Export
```

### Filtering Criteria

#### CPC Whitelist (84.3% of records included via CPC)
Patents matching any of the following CPC code patterns:
- **`^Y02T`** — Climate change mitigation technologies related to transportation
- **`^B60L`** — Propulsion of electrically-propelled vehicles; charging infrastructure
- **`^B60K`** — Arrangement or mounting of propulsion units or energy transmission
- **`^B60W`** — Conjoint control of vehicle sub-units (HEV/EV control systems)
- **`^H02J`** — Circuit arrangements for supplying or distributing electric power; charging
- **`^H02P`** — Control or regulation of electric motors, generators, or converters
- **`^H02K`** — Dynamo-electric machines (motors/generators)
- **`^H01M`** — Electrochemical cells, batteries, fuel cells (traction batteries)

#### Keyword Matching (15.7% of records included via keywords)
Patents containing EV-related keywords in title, abstract, or claims:
- Electric vehicle, battery pack, battery module, BMS
- State of charge, state of health, thermal runaway
- Traction motor, inverter, DC fast charging
- On-board charger, off-board charger
- CCS, CHAdeMO, V2G, V2H, bidirectional charging

### Inclusion Statistics
- **CPC-matched:** 486,139 records (84.3%)
- **Keyword-matched:** 90,535 records (15.7%)

### Schema & Documentation
- **Schema Files:** `metadata/schema_patents.json`, `metadata/schema_applications.json`
- **Manifest:** `metadata/manifest.json` (complete file inventory & metadata)
- **Provenance:** `data/provenance/sources.json` (source file tracking)

---

## Data Fields

### Core Metadata Fields
| Field | Type | Description |
|-------|------|-------------|
| `doc_type` | string | Document type: "grant" or "application" |
| `is_grant` | boolean | True if granted patent, False if application |
| `publication_number` | string | USPTO publication number (raw doc-number) |
| `pub_country` | string | Country code (typically "US") |
| `pub_kind` | string | Kind code (e.g., "B2", "A1") |
| `publication_id_full` | string | Complete canonical ID (e.g., US11234567B2) |
| `application_number` | string | Application number |
| `filing_date` | date | Filing date (YYYY-MM-DD) |
| `pub_date` | date | Publication/grant date (YYYY-MM-DD) |
| `title` | string | Patent title |
| `abstract` | string | Patent abstract |
| `assignees` | array[string] | List of assignee organization names |
| `inventors` | array[string] | List of inventor names |
| `cpc` | array[string] | CPC classification codes |
| `n_claims` | integer | Total number of claims |
| `indep_claims` | integer | Number of independent claims |
| `year` | integer | Publication year |
| `ev_included_by` | string | Inclusion method: "cpc" or "keyword" |

---

## Known Limitations

1. **Assignee Normalization**
   - Organization name variations may exist (e.g., "Toyota Motor Corporation" vs "Toyota Motor Corp.")
   - Best-effort entity consolidation applied, but some organizations may remain split across variations
   - Recommendation: Apply post-processing entity resolution for high-precision assignee analytics

2. **CPC Code Evolution**
   - CPC classification system evolves over time with new codes and restructuring
   - Historical patents may use older CPC versions that differ from current taxonomy
   - Some patents may have been retroactively reclassified by USPTO

3. **Duplicate Records**
   - 5.1% duplication rate in source data (29,152 duplicates removed)
   - Duplicates appear to stem from USPTO bulk file overlaps or republication events
   - Canonical record selection based on first occurrence in data stream

4. **Keyword-Based Inclusion**
   - 15.7% of dataset included via keyword matching (no CPC match)
   - Keyword matching is supplementary to CPC filtering for recall improvement
   - May include some tangentially-related patents

5. **Data Completeness**
   - Assignee field: 64.0% completeness (some patents lack corporate assignees)
   - Abstract field: 99.8% completeness (1,017 records missing abstracts)
   - All other key fields: >99.8% completeness

---

## File Checksums

> **Note:** For integrity verification, use SHA256 checksums provided in `metadata/manifest.json`

---

## Usage Recommendations

### Loading Data

**Single Month:**
```python
import pandas as pd
df = pd.read_parquet('data/patents/patents_2024-01.parquet')
```

**All Patents:**
```python
import glob
files = glob.glob('data/patents/*.parquet')
df = pd.concat([pd.read_parquet(f) for f in files], ignore_index=True)
```

**Combined Dataset (Patents + Applications):**
```python
patent_files = glob.glob('data/patents/*.parquet')
app_files = glob.glob('data/applications/*.parquet')
df_all = pd.concat(
    [pd.read_parquet(f) for f in patent_files + app_files], 
    ignore_index=True
)
```

---

## License & Attribution

**Source:** USPTO bulk patent publications (public domain, 17 U.S.C. §105)  
**License:** Arbitr Inc Commercial Dataset License v1.1 ([LICENSE_Arbitr_Commercial.txt](file:///c:/Users/E15/Desktop/utspo/arbitr-uspto-ev/LICENSE_Arbitr_Commercial.txt))  
**Disclaimer:** No affiliation or endorsement by USPTO is implied.

---

## Build Information

- **Dataset Version:** v1.0
- **Build Date:** 2025-11-16
- **Source Files Processed:**
  - 573 granted patent bulk files (ipg*.zip)
  - 607 application bulk files (I*.tar)
- **Processing Pipeline:** [uspto.py](file:///c:/Users/E15/Desktop/utspo/uspto.py)
- **Dataset Location:** [arbitr-uspto-ev/](file:///c:/Users/E15/Desktop/utspo/arbitr-uspto-ev/)

---

**Report Generated:** 2025-12-17  
**Analyst:** Automated QC Pipeline