Aakash Kolekar
Author directory2026
A Pinch of SFT, A Dash of RL: When Reinforcement Learning Helps Long-Horizon Advertising Agents
Aakash Kolekar | Sahika Genc | Bunyamin Sisman | Shahriar Shariat | Shree Vandana Kachroo | Avishek Saha | Qianli Wu | Ari Singer | Benoit Dumoulin
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing: Industry Track
Aakash Kolekar | Sahika Genc | Bunyamin Sisman | Shahriar Shariat | Shree Vandana Kachroo | Avishek Saha | Qianli Wu | Ari Singer | Benoit Dumoulin
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing: Industry Track
Enterprise analytics agents solve long-horizon tool-use problems over distributed business data, requiring retrieval, reasoning, API calls, code execution, and adaptation to intermediate observations. Supervised fine-tuning (SFT) calibrates tool syntax and teacher-supported behavior, whereas reinforcement learning (RL) can explore reward-supported behaviors beyond demonstrations; applied uniformly, however, RL can perturb already-calibrated skills. We study how to balance SFT and RL under production-mirroring beta APIs. We observe that, in our controlled experiment, checkpoint trajectories retrospectively separated into three regimes: Imitation, where SFT captured reliable teacher behavior; Lift, where both stages helped; and Discovery, where useful reward-observable behavior lay outside reliable teacher support. We leverage this prospectively, using teacher support and reward-observable headroom to route features to SFT only, SFT→RL, increased RL allocation, or further environment development. Across 18 subsequent feature-specific experiments, the diagnostic predicted 15/18 observed trajectories. On GPT-OSS 120B, targeted SFT→RL produced positive point estimates on 7/8 advertiser skills relative to a frontier Control; five positive gains had paired 95% confidence intervals excluding zero, while one skill had a confidence-supported regression. The largest gain was non-disclosure (+11.27 points; 95% CI [+9.72, +12.82]). A separate SME audit surfaced that targeted RL reduces standard leakage from 11.8% to 2.9% and adversarial leakage from 22.9% to 6.8% relative to SFT while preserving actionability (86.2% to 85.7%). In a matched uniform-versus-targeted comparison with shared rewards and optimization, targeted RL improved the seven-skill mean delta from +1.62 to +3.57 while using 43% less incremental RL compute.
2025
To Answer or Not to Answer (TAONA): A Robust Textual Graph Understanding and Question Answering Approach
Yuchen Yan | Aakash Kolekar | Sahika Genc | Wenju Xu | Edward W Huang | Anirudh Srinivasan | Mukesh Jain | Qi He | Hanghang Tong
Findings of the Association for Computational Linguistics: EMNLP 2025
Yuchen Yan | Aakash Kolekar | Sahika Genc | Wenju Xu | Edward W Huang | Anirudh Srinivasan | Mukesh Jain | Qi He | Hanghang Tong
Findings of the Association for Computational Linguistics: EMNLP 2025
Recently, textual graph-based retrieval-augmented generation (GraphRAG) has gained popularity for addressing hallucinations in large language models when answering domain-specific questions. Most existing studies assume that generated answers should comprehensively integrate all relevant information from the textual graph. However, this assumption may not always hold when certain information needs to be vetted or even blocked (e.g., due to safety concerns). In this paper, we target two sides of textual graph understanding and question answering: (1) normal question Answering (A-side): following standard practices, this task generates accurate responses using all relevant information within the textual graph; and (2) Blocked question answering (B-side): A new paradigm where the GraphRAG model must effectively infer and exclude specific relevant information in the generated response. To address these dual tasks, we propose TAONA, a novel GraphRAG model with two variants: (1) TAONA-A for A-side task, which incorporates a specialized GraphEncoder to learn graph prompting vectors; and (2) TAONA-B for B-side task, employing semi-supervised node classification to infer potential blocked graph nodes. Extensive experiments validate TAONA’s superior performance for both A-side and B-side tasks.