AQL-Lite: Enabling Efficient Knowledge Acquisition for Arabic LLMs via Data-Centric Continual Pretraining
Organizations: National School of Artificial Intelligence (ENSIA), Algiers, Algeria · Nojoom AI
Abstract
Training Arabic large language models faces challenges from noisy web data, dialectal variation, and the high cost of continual pretraining (CPT). We introduce AQL-Lite (AQL: Arabic Quality Language), a time- and resource-efficient framework for adapting a multilingual LLM to Modern Standard Arabic (MSA). AQL-Lite couples a quality-first curation pipeline (structural cleaning, heuristic and model-based filtering, MSA selection, and deduplication) with a partial-parameter CPT recipe that trains RS-LoRA adapters across the network together with the last eight transformer blocks and the embedding matrix, under layer-wise learning rates. At a matched 1B-token budget, CPT on AQL-curated data raises a four-benchmark Arabic mean by 3.51 points over CPT on raw web text, which yields no gain over the base model. In a controlled 5B-token comparison, AQL-Lite recovers 94% of the gain of full-parameter CPT (mean 73.19 vs. 73.58) in 52% of the wall-clock time and outperforms adapter-only baselines on every benchmark, and a component ablation shows that adapters, unfrozen blocks, and embedding training each contribute. Scaled to 40B MSA tokens and instruction-tuned on one million examples, the resulting 12B model scores 75.3 on the seven-benchmark Open Arabic LLM Leaderboard v2 (OALL v2) suite. These results suggest that partial-parameter CPT on a carefully curated corpus is a practical route to efficient MSA adaptation.
Figures & tables
| Stage | Tokens (B) | Retention |
|---|---|---|
| Raw crawl | 885 | 100.0% |
| Stages 1–2 (structural + heuristic quality) | 325 | 36.7% |
| Stage 3 (MSA selection) | 275 | 31.1% |
| Stages 4–5 (model-based + dedup) | 215 | 24.3% |
| Rule (on clean_text ) | Threshold |
|---|---|
| Min / max tokens per document | |
| Arabic character ratio † | |
| Digit + punct. + symbol ratio | |
| Max repeated-character run | |
| Repeated token 4-gram fraction | |
| Unique-token ratio |
| Method | Time | ArabicMMLU | AlGhafa | AraTrust | Arabic EXAMS | Mean |
|---|---|---|---|---|---|---|
| Gemma 3 12B PT | – | 65.56 | 60.68 | 87.01 | 54.38 | 66.91 |
| Full CPT | 121h | 68.92 | 77.33 | 89.22 | 58.85 | 73.58 |
| LoRA-only | 17h | 66.43 | 71.11 | 87.75 | 55.68 | 70.24 |
| RS-LoRA | 24h | 66.57 | 72.81 | 88.27 | 55.87 | 70.88 |
| AQL-Lite (ours) | 63h | 68.26 | 78.00 | 89.15 | 57.36 | 73.19 |
| Data (1B tok.) | ArMMLU | AlGhafa | AraTr. | EXAMS | Mean |
|---|---|---|---|---|---|
| Base (no CPT) | 65.56 | 60.68 | 87.01 | 54.38 | 66.91 |
| Raw crawl | 65.37 | 59.32 | 88.06 | 54.46 | 66.80 |
| Stages 1–2 | 65.61 | 62.77 | 88.12 | 53.28 | 67.45 |
| Stages 1–5 (AQL) | 66.39 | 69.84 | 88.83 | 56.17 | 70.31 |
| Config. (5B tok.) | ArMMLU | AlGhafa | AraTr. | EXAMS | Mean |
|---|---|---|---|---|---|
| RS-LoRA only | 66.57 | 72.81 | 88.27 | 55.87 | 70.88 |
| Unfreeze last 8 only | 64.74 | 63.84 | 88.42 | 54.85 | 67.96 |
| RS-LoRA + emb. | 67.28 | 75.23 | 88.12 | 55.43 | 71.52 |
| RS-LoRA + unfreeze | 66.89 | 74.91 | 88.84 | 56.26 | 71.73 |
| AQL-Lite (full) | 68.26 | 78.00 | 89.15 | 57.36 | 73.19 |
| Full CPT | 68.92 | 77.33 | 89.22 | 58.85 | 73.58 |
| Model | Mean | AlGhafa | ArabicMMLU | Arabic EXAMS | MadinahQA | AraTrust | ALRAGE | ArbMMLU-HT |
|---|---|---|---|---|---|---|---|---|
| Reported by the HELM Arabic leaderboard | ||||||||
| Gemini 2.5 Flash | 81.7 | 78.0 | 81.6 | 63.2 | 85.0 | 93.9 | 89.5 | 80.6 |
| GPT-5.1 (2025-11-13) | 80.9 | 79.1 | 80.3 | 63.1 | 80.4 | 94.1 | 90.9 | 78.4 |
| Qwen3 235B A22B Instruct | 78.6 | 77.3 | 76.9 | 59.0 | 77.7 | 91.7 | 89.0 | 78.3 |
| Llama 4 Scout Instruct | 74.6 | 77.5 | 73.4 | 60.0 | 72.5 | 89.1 | 81.1 | 68.6 |
| ALLaM-7B-Instruct-preview | 69.9 | 70.0 | 69.4 | 55.0 | 68.7 | 83.7 | 85.2 | 57.1 |
Appendix figures & tables6 assets
Supplementary material from the paper’s appendix.
Appendix
| Metric | Value |
|---|---|
| Eval loss | 0.00346 |
| Accuracy | 0.99964 |
| Macro-F1 | 0.99963 |
| Macro-Precision | 0.99956 |
| Macro-Recall | 0.99970 |
| Metric | Value | Notes |
|---|---|---|
| Eval loss | 0.0834 | Multi-task objective |
| Quality MSE | 0.00523 | Lower is better |
| Toxicity Acc / F1 | 0.958 / 0.958 | Binary head |
| Sexual Acc / F1 | 0.994 / 0.975 | Binary head |
| Violence Acc / F1 | 0.984 / 0.969 | Binary head |
| Harm Acc / F1 | 0.940 / 0.857 | Most ambiguous |
| Rule | Condition | Threshold |
|---|---|---|
| Quality | 0.7 | |
| Toxicity | 0.5 | |
| Hate | 0.5 | |
| Harm | 0.4 | |
| Sexual | 0.5 | |
| Violence | 0.5 |
| Setting | Value |
|---|---|
| Shared by all 5B-token runs | |
| Sequence length | 4096 (packed) |
| Precision | bfloat16 |
| Gradient clipping | 1.0 |
| Gradient accumulation | 16 |
| Parallelism | DeepSpeed ZeRO-2 |