README.md

---
language: en
license: apache-2.0
tags:
- sentence-embeddings
- transformers
- bert
- contrastive-learning
datasets:
- snli
---

# Embedder (SNLI)

## Model Description
A lightweight BERT-style encoder trained from scratch on SNLI entailment pairs using an in-batch contrastive loss and mean pooling.

## Training Data
- Dataset: SNLI (`datasets` library)
- Filter: label == entailment
- Subsample: 50,000 pairs from the training split
- Corpus for tokenizer: premises + hypotheses from the filtered pairs

## Tokenizer
- Type: WordPiece
- Vocab size: 30,000
- Min frequency: 2
- Special tokens: `[PAD] [UNK] [CLS] [SEP] [MASK]`
- Max sequence length: 128

## Architecture
- Model: `BertModel` (trained from scratch)
- Layers: 6
- Hidden size: 384
- Attention heads: 6
- Intermediate size: 1536
- Max position embeddings: 128

## Training Procedure
- Loss: in-batch contrastive loss (temperature = 0.05)
- Pooling: mean pooling over token embeddings
- Normalization: L2 normalize sentence embeddings
- Optimizer: AdamW
- Learning rate: 3e-4
- Batch size: 64
- Epochs: 2
- Device: CUDA if available, else MPS on macOS, else CPU

## Intended Use
- Learning/demo purposes for embedding training and similarity search
- Not intended for production use

## Limitations
- Trained from scratch; quality is lower than pretrained encoders
- Trained only on SNLI entailment pairs
- No downstream evaluation provided

## How to Use
from transformers import BertModel, BertTokenizerFast

model_id = "your-username/embedder-snli"
tokenizer = BertTokenizerFast.from_pretrained(model_id)
model = BertModel.from_pretrained(model_id)

## Citation
@inproceedings{bowman2015snli,
  title={A large annotated corpus for learning natural language inference},
  author={Bowman, Samuel R. and Angeli, Gabor and Potts, Christopher and Manning, Christopher D.},
  booktitle={Proceedings of the 2015 Conference on Empirical Methods in Natural Language Processing},
  year={2015}
}