---
license: apache-2.0
base_model: Qwen/Qwen2.5-0.5B-Instruct
library_name: peft
tags:
  - grpo
  - trl
  - autodata
  - synthetic-data
datasets:
  - ligaments-dev/autodata-grpo-cs
---

# autodata-policy-cs

A **Qwen2.5-0.5B-Instruct** policy fine-tuned with **GRPO** (Group Relative Policy Optimization)
on synthetic CS-reasoning data generated by **Autodata Studio** — an implementation of the
agentic self-instruct loop from *Autodata: An agentic data scientist to create high-quality
synthetic data* (arXiv:2606.25996v2).

This is a **testing-phase / infrastructure-validation run**, not a production model. Its purpose
was to prove the full pipeline end to end on real hardware.

## What this run proved

| Stage | Result |
|-------|--------|
| 72B challenger generates calibrated CS questions | ✅ 5/8 source docs produced a real weak/strong gap (30–60 pts) |
| Curated data pushed to the Hub | ✅ [`ligaments-dev/autodata-grpo-cs`](https://huggingface.co/datasets/ligaments-dev/autodata-grpo-cs) |
| GRPO training on HF Jobs (A10G, 24GB) | ✅ 100 steps, LoRA, programmatic reward, ~17 min |
| Trained adapter pushed to the Hub | ✅ this repo |

## Honest limitations of this run

- **Reward did not improve.** Mean reward oscillated around 0.47–0.55 across all 100 steps
  (no upward trend). The model was *trained*, but not measurably *improved*.
- **Root cause:** `completions/clipped_ratio = 1.0` — every generation hit the 256-token cap
  and never emitted a stop token, so the token-overlap reward stayed ~constant and GRPO had no
  usable gradient.
- **Tiny dataset:** only 5 prompts → 20 epochs of overfitting, no generalization signal.

## What a real (improving) run needs

1. **More data** — hundreds of accepted prompts, not 5.
2. **Fix completion termination** — investigate why EOS is never emitted; raise
   `max_completion_length` and/or correct the chat/generation config.
3. **A richer reward** — swap the lexical-overlap proxy for the paper's rubric/LLM-judge reward,
   or add a stop-token / brevity shaping term.
4. **Scale the GPU** — move from `a10g-small` to `a100-large` once the dataset and reward are sound.

## Training configuration

- Base model: `Qwen/Qwen2.5-0.5B-Instruct`
- Method: GRPO + LoRA (r=16, alpha=32, q/k/v/o projections)
- Reward: token-F1 overlap vs. reference answer + length/format shaping (programmatic, no API)
- Steps: 100, lr 1e-5, num_generations 8, max_completion_length 256, bf16
- Hardware: 1× A10G (24 GB) via HF Jobs

## Usage

```python
from peft import PeftModel
from transformers import AutoModelForCausalLM, AutoTokenizer

base = AutoModelForCausalLM.from_pretrained("Qwen/Qwen2.5-0.5B-Instruct")
model = PeftModel.from_pretrained(base, "ligaments-dev/autodata-policy-cs")
tok = AutoTokenizer.from_pretrained("ligaments-dev/autodata-policy-cs")
```