gpt2-small_classifier

Fine-Tuned GPT-2 Sentiment Classifier (IMDB)

This release contains the fine-tuned model weights (gpt2-small_classifier.pth) for the Binary Sentiment Analysis task. These weights allow users to run inference or evaluation immediately without needing to retrain the model from scratch.

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Performance Metrics

The model was fine-tuned on the IMDB Large Movie Review Dataset (25,000 training examples) and evaluated on the official test set (25,000 examples).

Metric	Value
Test Accuracy	91.83%
Test Loss	0.2026
Base Model	GPT-2 Small (124M)

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Usage Instructions

1. Download gpt2-small_classifier.pth from the Assets section below.
2. Place the file in the classification-finetuning/model_weights/ directory.
3. Run the main.ipynb notebook. Set MODE = "inference" or run the evaluation cells. The pipeline will detect the weights:

   # Expected output:
   --- PREPARING FOR INFERENCE ---
   Loading trained classifier from: ./model_weights/gpt2-small_classifier.pth
   Moving model to mps...
   

Critical Requirement:
These weights are strictly coupled to the GPT-2 Small (124M) architecture with a custom 2-class Classification Head.

• Do not try to load these into gpt2-medium or other sizes.
• Do not try to load these into a standard Hugging Face model class directly; they require the custom GPTClassifier wrapper defined in main.ipynb.

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Generated by the classification-finetuning/main.ipynb pipeline on Apple Silicon (M3 Pro)