File size: 5,370 Bytes
1496dfe 2eb9193 1496dfe 2eb9193 1496dfe | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 | # ReCon: Contrastive Explanation Model for OWL Reasoning (LoRA)
## Model Details
### Model Description
ReCon is a LoRA fine-tuned language model based on **meta-llama/Llama-3.1-8B-Instruct**, designed to generate **contrastive natural language explanations** for OWL reasoning tasks.
The model translates structured outputs from a Description Logic (DL) reasoner into human-readable explanations that answer:
> *“Why does fact A satisfy a class expression while foil B does not?”*
Unlike standard explanations, ReCon focuses on **contrastive reasoning**, highlighting:
* **Common evidence** (shared properties)
* **Differences** (missing or distinguishing properties)
* **Conflicts** (inconsistencies)
This work is part of a system combining:
* Symbolic reasoning (OWL reasoner)
* Natural language explanation (LLM)
* Graph-based visualization
---
### Key Contributions
* Converts **formal OWL reasoning outputs (JSON)** into natural language
* Reduces hallucination via **strict evidence-grounded prompting**
* Supports **contrastive explanations (fact vs foil)**
* Integrated into:
* Flask-based UI
---
### Model Information
* **Developed by:** Akash, Ashik and Sam (DICE Group, Paderborn University)
* **Model type:** Causal Language Model (LoRA adapted)
* **Base model:** meta-llama/Llama-3.1-8B-Instruct
* **Language(s):** English (primary), German (supported)
* **License:** Same as base model (Llama 3.1 license)
---
## Intended Use
### Direct Use
* OWL reasoning explanation generation
* Contrastive reasoning (fact vs foil)
* Explainable AI (XAI) workflows
* Knowledge graph interpretation
### Downstream Use
* Integration with reasoning pipelines
* Explainability layer for symbolic + neural systems
* Educational tools for ontology reasoning
### Out-of-Scope Use
* General chatbot usage
* Open-ended reasoning without structured input
* Tasks requiring external world knowledge
---
## How to Use
```python
from transformers import AutoModelForCausalLM, AutoTokenizer
from peft import PeftModel
base_model = "meta-llama/Llama-3.1-8B-Instruct"
tokenizer = AutoTokenizer.from_pretrained(base_model)
base = AutoModelForCausalLM.from_pretrained(base_model)
model = PeftModel.from_pretrained(base, "vanishingMonk/Contrastive_Explainer")
```
---
## Training Details
### Training Objective
The model is fine-tuned to generate **faithful, structured explanations grounded strictly in reasoning evidence**, rather than free-form generation.
---
### Training Data
Training data was constructed from OWL reasoning tasks using datasets such as:
* Family ontology
* Carcinogenesis
* Lymphography
Each sample includes:
* Class expression
* Fact–foil pair
* Structured reasoning output:
* `common`
* `different`
* `conflicts`
Both formats were used:
* Instruction-based samples
* Multi-turn chat-based samples
---
### Prompt Engineering
A strict **three-layer prompt structure** was used:
1. **System Prompt**
* Enforces evidence-only reasoning
* Controls output format
* Language constraints
2. **Role Prompt**
* Defines model as:
> "Formal logician + OWL reasoner debugger"
3. **Context Prompt**
* Defines semantics of:
* common / different / conflicts
* Enforces exact reasoning patterns
* Fixes verdict:
* FACT = satisfies
* FOIL = fails
This significantly reduces hallucinations and improves logical consistency.
---
### Training Setup
* **Method:** LoRA (PEFT)
* **Rank (r):** 8
* **Alpha:** 16
* **Target modules:**
* q_proj, v_proj, o_proj
* gate_proj, up_proj, down_proj
* **Precision:** bf16
* **Framework:** Torchtune
---
## Evaluation
### General Reasoning Benchmarks
| Benchmark | Metric | Fine-tuned | Base |
| -------------- | -------- | ---------- | ----- |
| ARC-Challenge | Accuracy | 0.544 | 0.553 |
| HellaSwag (EN) | Accuracy | 0.790 | 0.796 |
| HellaSwag (DE) | Accuracy | 0.615 | 0.615 |
| TruthfulQA | Accuracy | 0.533 | 0.545 |
→ Minimal degradation in general reasoning performance
---
### Explanation Quality
| Metric | Fine-tuned | Base |
| --------- | ---------- | ------ |
| ROUGE-1 | 0.4066 | 0.5845 |
| ROUGE-2 | 0.1424 | 0.3443 |
| ROUGE-L | 0.2981 | 0.4013 |
| BERTScore | 0.8475 | 0.8705 |
**Important:**
Lower ROUGE/BERTScore reflects **stylistic differences**, not worse reasoning.
Human evaluation shows **higher logical fidelity and stability**.
---
## System Integration
ReCon is part of a full pipeline:
1. OWL reasoner generates contrastive explanation (JSON)
2. ReCon converts it into natural language
3. Graphviz generates a visual explanation
4. UI presents:
* Explanation
* Graph
* Chat interface
Also integrated into:
* Flask web interface
* Protégé plugin
---
## Limitations
* Requires structured reasoning input
* Cannot perform standalone logical inference
* Sensitive to prompt format
* May hallucinate if constraints are relaxed
---
## Future Work
* Scaling to larger ontologies
* Support for more DL constructs
---
## Citation
This model is part of an academic project at Paderborn University.
If you use this model, please reference this repository.
---
## Contact
For questions, collaborations, or research discussions, feel free to reach out to Akash. Email: akbaum@mail.uni-paderborn.de
|