Overview
This project fine-tunes a LoRA adapter for Qwen2.5-3B-Instruct to evaluate
technical interview answers against a provided question and scoring rubric.
The model is designed to return a JSON object with:
score: integer from 0 to 5
max_score: integer, always 5
justification: explanation for the score
strengths: demonstrated strengths
improvements: suggested improvements
Base model
Qwen/Qwen2.5-3B-Instruct
Training approach
- Method: QLoRA with 4-bit model loading
- Training examples: 480 synthetic examples
- Validation examples: 60 synthetic examples
- Held-out test examples: 60
- Adapter rank: 16
- Epochs configured: 3
Evaluation
The same held-out test examples were used for the base and fine-tuned model.
Results below should be interpreted as agreement with synthetic expected labels,
not as proof of real-world interviewer reliability.
Table with columns: Metric, Base model, Fine-tuned model| Metric | Base model | Fine-tuned model |
|---|
| Valid JSON (%) | 98.33% | 100.0% |
| Schema-valid (%) | 98.33% | 100.0% |
| Score MAE | 1.8814 | 2.0333 |
| Exact score accuracy (%) | 15.25% | 21.67% |
Intended use
Research, experimentation, and educational demonstrations of small-model
fine-tuning for structured technical-answer evaluation.
Limitations
- Training and evaluation labels are synthetic.
- The model can produce incorrect scores or explanations.
- JSON validity does not guarantee scoring correctness.
- Human review is recommended before using scores for hiring or other
consequential decisions.
Usage
Load the compatible base model and adapter using a compatible Transformers
and PEFT setup. The adapter is not a standalone full model.
License
Check the base model's license and applicable terms before redistributing or
using this adapter. This model card does not grant rights beyond those terms.