The Beaver reward model is a preference model trained using the PKU-SafeRLHF dataset. It can play a role in the safe RLHF algorithm, helping the Beaver model become more helpful.

Developed by: the PKU-Alignment Team.
Model Type: An auto-regressive language model based on the transformer architecture.
License: Non-commercial license.
Fine-tuned from model: LLaMA, Alpaca.

Model Sources

Repository: https://github.com/PKU-Alignment/safe-rlhf
Beaver: https://huggingface.co/PKU-Alignment/beaver-7b-v2.0
Dataset: https://huggingface.co/datasets/PKU-Alignment/PKU-SafeRLHF
Reward Model: https://huggingface.co/PKU-Alignment/beaver-7b-v2.0-reward
Cost Model: https://huggingface.co/PKU-Alignment/beaver-7b-v2.0-cost
Dataset Paper: https://arxiv.org/abs/2307.04657
Paper: https://arxiv.org/abs/2310.12773

How to Use the Reward Model

python

import torch
from transformers import AutoTokenizer
from safe_rlhf.models import AutoModelForScore

model = AutoModelForScore.from_pretrained('PKU-Alignment/beaver-7b-v2.0-reward', torch_dtype=torch.bfloat16, device_map='auto')
tokenizer = AutoTokenizer.from_pretrained('PKU-Alignment/beaver-7b-v2.0-reward')

input = 'BEGINNING OF CONVERSATION: USER: hello ASSISTANT:Hello! How can I help you today?'

input_ids = tokenizer(input, return_tensors='pt')
output = model(**input_ids)
print(output)

# ScoreModelOutput(
#     scores=tensor([[[-5.5000],
#          [-0.1650],
#          [-4.0625],
#          [-0.0522],
#          [-1.0859],
#          [-0.4277],
#          [-2.3750],
#          [-2.5781],
#          [-1.0859],
#          [-1.1250],
#          [-0.3809],
#          [-1.0000],
#          [-1.2344],
#          [-0.7344],
#          [-1.3438],
#          [-1.2578],
#          [-0.4883],
#          [-1.1953],
#          [-1.1953],
#          [ 0.0908],
#          [-0.8164],
#          [ 0.1147],
#          [-0.1650],
#          [-0.4238],
#          [ 0.3535],
#          [ 1.2969],
#          [ 0.7461],
#          [ 1.8203]]], grad_fn=<ToCopyBackward0>),
#     end_scores=tensor([[1.8203]], grad_fn=<ToCopyBackward0>),
#     last_hidden_state=tensor([[[ 0.4766, -0.1787, -0.5312,  ..., -0.0194,  0.2773,  0.7500],
#          [ 0.5625,  2.0000,  0.8438,  ...,  1.8281,  1.0391, -0.6914],
#          [ 0.6484,  0.0388, -0.7227,  ..., -0.4688,  0.2754, -1.4688],
#          ...,
#          [ 0.2598,  0.6758, -0.6289,  ..., -1.0234,  0.5898,  1.4375],
#          [ 1.7500, -0.0913, -1.1641,  ..., -0.8438,  0.4199,  0.8945],
#          [ 1.8516, -0.0684, -1.1094,  ...,  0.1885,  0.4980,  1.1016]]],
#        dtype=torch.bfloat16, grad_fn=<ToCopyBackward0>),
#     end_last_hidden_state=tensor([[ 1.8516, -0.0684, -1.1094,  ...,  0.1885,  0.4980,  1.1016]],
#        dtype=torch.bfloat16, grad_fn=<ToCopyBackward0>),
#     end_index=tensor([27])
# )