Toxic Content Classification

Comprehensive text moderation foundation with LSTM baseline and DistilBERT PEFT-LoRA fine-tuning

Week 1
Duration: 1 week
NLP, PEFT-LoRA, LSTM, Data Pipeline

Project Overview

Understanding the challenge and solution approach

Problem Statement

Build a robust text moderation foundation for a multi-modal toxic content moderation system, requiring both baseline and advanced models for comprehensive content classification across 9 toxic categories.

Solution Approach

Developed two complementary models: a Bidirectional LSTM baseline for efficiency and a DistilBERT with PEFT-LoRA for advanced performance, along with a complete data pipeline for preprocessing and evaluation.

Expected Outcome

Create a comprehensive text moderation foundation with 94% accuracy baseline and efficient transformer fine-tuning, ready for extension to dual-stage and multi-modal moderation systems.

Model Comparison & Architecture

Two complementary approaches for toxic content classification

Model Performance Comparison

Aspect LSTM Baseline DistilBERT + LoRA
Performance 94% Accuracy, 82% Macro F1 Eval Loss: 0.41, High Precision
Training Cost Low computational requirements Medium, efficient with PEFT
Inference Speed High speed, suitable for edge Medium, optimized for NLP stack
Architecture Bidirectional LSTM + Dense layers Transformer + LoRA adapters
Use Case Baseline, resource-constrained Production, high accuracy

Methodology & Implementation

Comprehensive data pipeline and model development approach

  1. Data Pipeline Development: Built a complete preprocessing pipeline including text cleaning, tokenization, label encoding, and stratified splitting for 9 toxic content categories.
  2. LSTM Baseline Model: Implemented a Bidirectional LSTM architecture with embedding layers, achieving 94% accuracy with efficient training and inference capabilities.
  3. DistilBERT PEFT-LoRA Implementation: Applied Parameter Efficient Fine-Tuning with LoRA adapters to DistilBERT, enabling efficient fine-tuning while maintaining high performance.
  4. Model Training & Optimization: Configured optimal hyperparameters, implemented early stopping, and addressed class imbalance through SMOTE and weighted loss functions.
  5. Comprehensive Evaluation: Conducted benchmarking using multiple metrics including accuracy, precision, recall, and F1-score across all content categories.
  6. Production Preparation: Created modular code structure, versioned artifacts, and prepared models for deployment in the dual-stage moderation system.

Results & Performance

Key metrics and achievements from the toxic content classification model

94.2%
Overall Accuracy
92.8%
Precision
93.5%
Recall
93.1%
F1-Score

Key Achievements

  • Successfully reduced model size by 60% while maintaining 94%+ accuracy
  • Achieved 3x faster inference time compared to full fine-tuning
  • Demonstrated robust performance across different content categories
  • Created a production-ready model suitable for real-time applications

Technical Stack

Technologies and frameworks used in the project

DistilBERT PEFT-LoRA LSTM TensorFlow PyTorch Transformers Hugging Face Python Scikit-learn NumPy Pandas NLTK

Project Links & Resources

Access to models, code, and documentation

Challenges & Solutions

Key obstacles encountered and how they were overcome

  • Class Imbalance: Addressed imbalanced dataset using weighted loss functions and data augmentation techniques to ensure fair representation of all content categories.
  • Computational Efficiency: Implemented PEFT techniques to reduce memory usage and training time while maintaining model performance, making it suitable for deployment on resource-constrained environments.
  • Model Interpretability: Added attention visualization and feature importance analysis to understand model decisions and ensure transparency in content moderation decisions.
  • Real-time Performance: Optimized inference pipeline and model architecture to achieve sub-second response times required for production deployment.
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