---
language:
- en
- de
tags:
- nsp
- next-sentence-prediction
- gpt
datasets:
  - wikipedia
metrics:
  - accuracy
---

# mGPT-nsp

mGPT-nsp is fine-tuned for Next Sentence Prediction task on the [wikipedia dataset](https://huggingface.co/datasets/wikipedia) using [multilingual GPT](https://huggingface.co/THUMT/mGPT) model. It was introduced in this [paper](https://arxiv.org/abs/2307.07331) and first released on this page.

## Model description

mGPT-nsp is a Transformer-based model which was fine-tuned for Next Sentence Prediction task on 11000 English and 11000 German Wikipedia articles. We use the same tokenization and vocabulary as the [mT5 model](https://huggingface.co/google/mt5-base).

## Intended uses

- Apply Next Sentence Prediction tasks. (compare the results with BERT models since BERT natively supports this task)
- See how to fine-tune an mGPT2 model using our [code](https://github.com/slds-lmu/stereotypes-multi/tree/main)
- Check our [paper](https://arxiv.org/abs/2307.07331) to see its results

## How to use

You can use this model directly with a pipeline for next sentence prediction.  Here is how to use this model in PyTorch:

### Necessary Initialization
```python
from transformers import MT5Tokenizer, GPT2Model
import torch
from huggingface_hub import hf_hub_download

class ModelNSP(torch.nn.Module):
    def __init__(self, pretrained_model="THUMT/mGPT"):
        super(ModelNSP, self).__init__()
        self.core_model = GPT2Model.from_pretrained(pretrained_model)
        self.nsp_head = torch.nn.Sequential(torch.nn.Linear(self.core_model.config.hidden_size, 300),
                                            torch.nn.Linear(300, 300), torch.nn.Linear(300, 2))

    def forward(self, input_ids, attention_mask=None):
        return self.nsp_head(self.core_model(input_ids, attention_mask=attention_mask)[0].mean(dim=1)).softmax(dim=-1)

model = torch.nn.DataParallel(ModelNSP().eval())
model.load_state_dict(torch.load(hf_hub_download(repo_id="tolga-ozturk/mGPT-nsp", filename="model_weights.bin")))
tokenizer = MT5Tokenizer.from_pretrained("tolga-ozturk/mGPT-nsp")
```

### Inference
```python
batch_texts = [("In Italy, pizza is presented unsliced.", "The sky is blue."),
    ("In Italy, pizza is presented unsliced.", "However, it is served sliced in Turkey.")]
encoded_dict = tokenizer.batch_encode_plus(batch_text_or_text_pairs=batch_texts, truncation="longest_first",padding=True, return_tensors="pt", return_attention_mask=True, max_length=256)
print(torch.argmax(model(encoded_dict.input_ids, attention_mask=encoded_dict.attention_mask), dim=-1))
```

### Training Metrics
<img src="https://huggingface.co/tolga-ozturk/mgpt-nsp/resolve/main/metrics.png">

## BibTeX entry and citation info

```bibtex
@misc{title={How Different Is Stereotypical Bias Across Languages?}, 
      author={Ibrahim Tolga Öztürk and Rostislav Nedelchev and Christian Heumann and Esteban Garces Arias and Marius Roger and Bernd Bischl and Matthias Aßenmacher},
      year={2023},
      eprint={2307.07331},
      archivePrefix={arXiv},
      primaryClass={cs.CL}
}
```

The work is done with Ludwig-Maximilians-Universität Statistics group, don't forget to check out [their huggingface page](https://huggingface.co/misoda) for other interesting works!