---
language: en
license: mit
library_name: transformers
tags:
- text-classification
- character-analysis
- plot-arc
- narrative-analysis
- deberta-v3
- binary-classification
datasets:
- custom
metrics:
- accuracy
- f1
model-index:
- name: plot-arc-classifier
  results:
  - task:
      type: text-classification
      name: Character Plot Arc Classification
    dataset:
      type: custom
      name: Character Arc Dataset
    metrics:
    - type: accuracy
      value: 0.796
      name: Accuracy
    - type: f1
      value: 0.796
      name: F1 Score (Strong Class)
    - type: precision
      value: 0.777
      name: Precision (Strong Class)
    - type: recall
      value: 0.816
      name: Recall (Strong Class)
base_model: microsoft/deberta-v3-xsmall
---

# Plot Arc Character Classifier

A DeBERTa-v3-XSmall model fine-tuned to classify fictional characters based on their plot arc potential.

## Model Description

This model classifies character descriptions into two categories:
- **STRONG** (label 1): Characters with both internal conflict and external responsibilities/events
- **WEAK** (label 0): Characters with no plot arc, pure internal conflict only, or pure external events only

The model fixes critical bias issues where simple background characters (shopkeepers, guards) were incorrectly classified as plot-significant.

## Training Data

- **Dataset Size**: 11,888 balanced examples (50/50 split)
- **Training Examples**: 9,510
- **Validation Examples**: 2,378
- **Source**: Custom 4-way classified character descriptions from literature

### Label Mapping
- **STRONG (1)**: Characters classified as "BOTH" (internal conflict + external events)
- **WEAK (0)**: Characters classified as "NONE", "INTERNAL", or "EXTERNAL"

## Training Details

- **Base Model**: microsoft/deberta-v3-xsmall (22M parameters)
- **Training Time**: ~15 minutes
- **Batch Size**: 8 (with gradient accumulation = 2)
- **Max Sequence Length**: 384 tokens
- **Learning Rate**: 5e-5 with warmup
- **Early Stopping**: Yes (stopped at 3.7/5 epochs)

## Performance

### Validation Metrics
| Metric | Score |
|--------|-------|
| Accuracy | 79.6% |
| F1 (Strong) | 79.6% |
| Precision (Strong) | 77.7% |
| Recall (Strong) | 81.6% |

### Synthetic Test Results
**100% accuracy** on diverse test cases including previously problematic examples:

| Character Type | Example | Prediction | Confidence |
|----------------|---------|------------|------------|
| Background (NONE) | Baker, Guard | WEAK ✅ | 98.9%, 98.5% |
| Pure Internal | Haunted Artist | WEAK ✅ | 93.9% |
| Pure External | Military Commander | WEAK ✅ | 94.5% |
| Both (Internal+External) | Conflicted King | STRONG ✅ | 95.1% |
| Both (Trauma+Mission) | PTSD Captain | STRONG ✅ | 95.5% |
| Both (Doubt+Quest) | Uncertain Prophet | STRONG ✅ | 96.0% |

**Key Achievement**: Fixed critical bias where simple background characters were incorrectly classified as plot-significant.

## Usage

```python
from transformers import AutoTokenizer, AutoModelForSequenceClassification
import torch

# Load model and tokenizer
tokenizer = AutoTokenizer.from_pretrained("plot-arc-classifier")
model = AutoModelForSequenceClassification.from_pretrained("plot-arc-classifier")

# Example usage
def classify_character(description):
    inputs = tokenizer(description, return_tensors="pt", truncation=True, max_length=384)
    
    with torch.no_grad():
        outputs = model(**inputs)
        probabilities = torch.nn.functional.softmax(outputs.logits, dim=-1)
        predicted_class = torch.argmax(probabilities, dim=-1).item()
    
    labels = {0: "WEAK", 1: "STRONG"}
    confidence = probabilities[0][predicted_class].item()
    
    return labels[predicted_class], confidence

# Test examples
examples = [
    "A baker who makes fresh bread daily and serves customers with a smile.",
    "A warrior haunted by past failures who must lead a desperate battle to save his homeland while confronting his inner demons.",
]

for desc in examples:
    label, conf = classify_character(desc)
    print(f"'{desc[:50]}...': {label} ({conf:.3f})")
```

## Model Improvements

This model addresses critical issues from previous versions:

1. **Fixed Bias**: No longer classifies simple background characters as STRONG
2. **Proper Discrimination**: Requires both internal and external elements for STRONG classification  
3. **Balanced Training**: 50/50 split prevents class imbalance issues
4. **Clean Taxonomy**: Based on proper 4-way character analysis

## Limitations

- Trained on English literary character descriptions
- May not generalize well to other domains (screenwriting, gaming, etc.)
- Performance may degrade on very short or very long descriptions
- Cultural bias toward Western narrative structures

## Ethical Considerations

This model is designed for narrative analysis and creative writing assistance. It should not be used to make judgments about real people or for any discriminatory purposes.

## Citation

If you use this model, please cite:

```bibtex
@misc{plot-arc-classifier-2024,
  title={Plot Arc Character Classifier},
  author={Generated with Claude Code},
  year={2024},
  url={https://huggingface.co/plot-arc-classifier}
}
```

## Training Infrastructure

- **Framework**: 🤗 Transformers
- **Hardware**: Apple Silicon (MPS)
- **Optimization**: Memory-optimized for MPS training
- **Early Stopping**: Enabled to prevent overfitting

---

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>