[ACL 2025 main] SCAR: Data Selection via Style Consistency-Aware Response Ranking for Efficient Instruction-Tuning of Large Language Models

Overview

SCAR is an innovative data selection method that enhances instruction-tuning for large language models. By leveraging style consistency-aware response ranking, SCAR identifies and selects the most beneficial training data for fine-tuning LLMs, ultimately improving their performance.

Installation

Ensure you have a Python 3.8+ environment. You can install SCAR using pip:

pip install scar-tool

Requirements

SCAR requires the following dependencies: torch>=2.3, transformers>=4.37, huggingface_hub>=0.23, scikit-learn, tqdm, nltk and datasketch. These will be automatically installed when you install SCAR via pip.

Usage

Basic Usage with Hugging Face Transformers

Here's a simple example of how to use the StyleRanker model with Hugging Face Transformers:

import torch
from transformers import AutoTokenizer
from style_ranker.ranker.model import StyleRanker

# Load the model and tokenizer
model_path = "lizhuang144/scar-gte-base"
model = StyleRanker.from_pretrained(model_path)
tokenizer = AutoTokenizer.from_pretrained(model_path)

# Prepare your data
instructions = ["Write a poem about spring", "Explain quantum computing"]
answers = ["I am sorry. Who are you? Why should I tell you anything about poem", "Quantum computing is a type of computation..."]

# Tokenize the inputs
max_length = 512
instruction_inputs = tokenizer(instructions, return_tensors='pt', padding=True, truncation=True, max_length=max_length)
answer_inputs = tokenizer(answers, return_tensors='pt', padding=True, truncation=True, max_length=max_length)
model.eval()
# Get the scores
with torch.no_grad():
    scores = model(
        instruction_inputs.input_ids,
        instruction_inputs.attention_mask,
        answer_inputs.input_ids,
        answer_inputs.attention_mask
    )

# Print the results
for instruction, answer, score in zip(instructions, answers, scores):
    print(f"Instruction: {instruction}")
    print(f"Answer: {answer}")
    print(f"Score: {score.item()}")
    print()

Advanced Usage

SCAR offers sophisticated capabilities for data filtering and ranking through its comprehensive pipeline. This allows you to fine-tune your selection process by choosing the top-k pairs with the highest scores, setting a ratio for selection, or applying a threshold for filtering.

The rank_and_filter function provides a powerful way to rank and filter instruction-answer pairs. Here's an example demonstrating its usage:

from style_ranker.rank import rank_and_filter
import torch
# Load the model and tokenizer
model_path = "lizhuang144/scar-gte-base"

# Prepare your data
instructions = ["Write a poem about spring", "Explain quantum computing", "Describe the water cycle"]
answers = ["I am sorry. Who are you? Why should I tell you anything about poem", "Quantum computing is a type of computation...",
           "The water cycle, also known as..."]

device = "cuda" if torch.cuda.is_available() else "cpu"

# Example 1: Using topk
topk_pairs = rank_and_filter(model_path, instructions, answers, topk=2, device=device)

# Example 2: Using threshold
threshold_pairs = rank_and_filter(model_path, instructions, answers, threshold=-2.0, device=device)

# Example 3: Using ratio
ratio_pairs = rank_and_filter(model_path, instructions, answers, ratio=0.5, device=device)

# Print results for each method
print("Top-k results:")
for instruction, answer, score in topk_pairs:
    print(f"Score: {score:.2f} | Instruction: {instruction}")

print("\nThreshold results:")
for instruction, answer, score in threshold_pairs:
    print(f"Score: {score:.2f} | Instruction: {instruction}")

print("\nRatio results:")
for instruction, answer, score in ratio_pairs:
    print(f"Score: {score:.2f} | Instruction: {instruction}")

Tip: Our models currently do not support non-English examples or automatically remove duplicates. To ensure better performance, please exclude non-English examples and perform de-duplication before applying our method.

Model List

We provide the following pre-trained SCAR models:

• lizhuang144/scar-gte-base: SCAR model trained using Alibaba-NLP/gte-base-en-v1.5 as the representation encoder.
• lizhuang144/scar-gte-large: SCAR model trained using Alibaba-NLP/gte-large-en-v1.5 as the representation encoder.
• lizhuang144/scar-roberta-base: SCAR model trained using FacebookAI/roberta-base as the representation encoder.

The models here are pre-trained on a dataset consisting primarily of open-domain data, available at data/ranker_data/mix_code_open/gpt_35.

Performance

SCAR demonstrates significant improvements in LLM performance when used for data filtering and selection. We evaluated our method using two LLMs: Olmo and Starcoder.

Olmo Performance

Dataset Size	L.C. WinRate
Full dataset (320k)	3.86
SCAR-filtered 10k	5.37
SCAR-filtered 5k	5.64
SCAR-filtered 2.5k	4.08

The official checkpoint allenai/OLMo-7B-SFT is trained on 320k data from allenai/tulu-v2-sft-mixture. We evaluate the performance of models trained with SCAR-filtered data using 10k, 5k, and 2.5k instruction-answer pairs. The evaluation metric is L.C. WinRate, which compares our model outputs with 'gpt-4-1106-preview' outputs using meta-llama/Llama-3-70b-chat-hf from Together AI as the judger on the AlpacaEval benchmark.

Starcoder Performance

Dataset Size	HumanEval (Python)	MultiPL-E (Java)	MultiPL-E (JavaScript)	MultiPL-E (C++)
	Pass@1 / Pass@10	Pass@1 / Pass@10	Pass@1 / Pass@10	Pass@1 / Pass@10
Full dataset (13k)	35.56/ 51.81	26.03 / 38.44	32.80 / 46.97	29.32 / 41.90
SCAR-filtered 10k	36.29 / 53.99	28.29 / 39.58	33.22 / 49.79	30.17 / 46.20
SCAR-filtered 5k	36.95 / 54.07	28.96 / 39.02	34.53 / 49.90	32.83 / 44.47
SCAR-filtered 2.5k	37.57 / 55.65	29.29 / 41.06	34.09 / 49.47	31.19 / 42.83

The official checkpoint 'bigcode/octocoder' is the 'bigcode/starcoder' fine-tuned on 13k data from 'bigcode/guanaco-commits'. We evaluated the performance using the bigcode-evaluation-harness. The performance of 'bigcode/octocoder' is obtained from the 'bigcode/bigcode-models-leaderboard'. We evaluated models on four datasets in four programming languages (Python, Java, C++, and JavaScript) and reported two execution accuracies (Pass@1 and Pass@10) for each dataset. We evaluated the performance of the model trained with SCAR-filtered data with 10k, 5k, and 2.5k instruction-answer pairs.

Key Components

• StyleRanker: A model for ranking instruction-answer pairs based on style consistency and data quality.
• Data Filtering: Scripts for filtering and selecting high-quality instruction-answer pairs.
• LLM Training: Scripts for fine-tuning large language models using the selected data.

Scripts

The scripts/ directory contains bash scripts for various tasks:

• data_synthesize.sh: Synthesizes 'referenced' and 'direct' responses based on the human responses for training the ranker. Please adjust the script arguments as needed.
• quality_measure.sh: Measures the quality of the collected responses using LLMs, utilized to train the ranker.
• train_ranker.sh: Trains the SCAR style ranker model. Please update the script arguments as needed.
• data_filter.sh: Ranks and filters instruction-answer pairs. Please update the script arguments as needed.
• train_llm.sh: This script fine-tunes a large language model using the filtered data. Review and update the script arguments accordingly to ensure proper training. The following additional packages are required to train the LLM: peft, trl, accelerate and deepspeed.

Ensure all dependencies are installed before running these scripts to achieve the best results.

Project Structure

The project is organized as follows:

• data/: Datasets for training and evaluation
  • llm_sft_data/: Training data for the large language model (code and open domain)
  • ranker_data/: Training data for the ranker (code and open domain)
• style_ranker/: Main package
  • consts.py
  • dedup.py: Near deduplication
  • llm/: LLM training (train.py)
  • rank.py: Ranking and filtering
  • ranker/: StyleRanker implementation
    • config.py, dataset.py, model.py, quality.py: Quality measure with LLMs like GPT-3.5-turbo
    • SCAR ranker training (train.py)
  • utils.py
• examples/: Example Python scripts
  • filter_pipeline.py, rank_pairs.py, remove_dupes.py, vicuna_converter.py
• scripts/: Example Bash scripts
  • data_synthesize.sh, data_filter.sh, quality_measure.sh, train_llm.sh, train_ranker.sh
• requirements.txt: List of dependencies
• setup.py: Installation script

Citation

@inproceedings{li-etal-2025-scar,
    title = "{SCAR}: Data Selection via Style Consistency-Aware Response Ranking for Efficient Instruction-Tuning of Large Language Models",
    author = "Li, Zhuang  and
      Hua, Yuncheng  and
      Vu, Thuy-Trang  and
      Zhan, Haolan  and
      Qu, Lizhen  and
      Haffari, Gholamreza",
    editor = "Che, Wanxiang  and
      Nabende, Joyce  and
      Shutova, Ekaterina  and
      Pilehvar, Mohammad Taher",
    booktitle = "Proceedings of the 63rd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)",
    month = jul,
    year = "2025",
    address = "Vienna, Austria",
    publisher = "Association for Computational Linguistics",
    url = "https://aclanthology.org/2025.acl-long.625/",
    pages = "12756--12790",
    ISBN = "979-8-89176-251-0"
}