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1. Enhancing LLM-Based Short Answer Grading with Retrieval-Augmented Generation

   https://doi.org/10.5281/zenodo.15870304  

   Chu, Yucheng; He, Peng; Li, Hang; Han, Haoyu; Yang, Kaiqi; Xue, Yu; Li, Tingting; Krajcik, Joseph; Tang, Jiliang (July 2025, International Educational Data Mining Society)

   Mills, Caitlin; Alexandron, Giora; Taibi, Davide; Lo_Bosco, Giosuè; Paquette, Luc (Ed.)

   Short answer assessment is a vital component of science education, allowing evaluation of students' complex three-dimensional understanding. Large language models (LLMs) that possess human-like ability in linguistic tasks are increasingly popular in assisting human graders to reduce their workload. However, LLMs' limitations in domain knowledge restrict their understanding in task-specific requirements and hinder their ability to achieve satisfactory performance. Retrieval-augmented generation (RAG) emerges as a promising solution by enabling LLMs to access relevant domain-specific knowledge during assessment. In this work, we propose an adaptive RAG framework for automated grading that dynamically retrieves and incorporates domain-specific knowledge based on the question and student answer context. Our approach combines semantic search and curated educational sources to retrieve valuable reference materials. Experimental results in a science education dataset demonstrate that our system achieves an improvement in grading accuracy compared to baseline LLM approaches. The findings suggest that RAG-enhanced grading systems can serve as reliable support with efficient performance gains. 

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2. D-RAG: A Privacy-Preserving Framework for Decentralized RAG using Blockchain

   https://doi.org/10.5121/csit.2025.150417  

   E_Andersen, Tessa; Avalos, Ayanna Marie; G_Dagher, Gaby; Long, Min (February 2025, Academy & Industry Research Collaboration)

   Retrieval Augmented Generation (RAG) has been a recent improvement in providing recent and accurate data to Large Language Models (LLMs). Although RAG has been successful in reducing hallucinations within LLMs, it remains susceptible to inaccurate and maliciously manipulated data. In this paper, we present Distributed-RAG (D-RAG), a novel blockchain-based framework designed to increase the integrity of the RAG system. D-RAG addresses the risks of malicious data by replacing the RAG’s traditionally centralized database with communities, each consisting of a database and a permissioned blockchain. The communities are based on different subjects, each containing experts in the field who verify data through a privacy-preserving consensus protocol before it is added to the database. A Retrieval Blockchain is also designed to communicate between the multiple communities. The miners on this Retrieval Blockchain are responsible for retrieving documents from the database for each query and ranking them using an LLM. These rankings are agreed upon, and the top ranked documents are provided to the LLM with the query to generate a response. We perform experiments on our proposed D-RAG framework, and our results show that our Retrieval Blockchain is scalable and our privacy-preserving consensus protocol maintains efficiency as community members increase. These results demonstrate that in a real-world application setting D-RAG is scalable in maintaining data integrity. 

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3. Real-time Factuality Assessment from Adversarial Feedback

   Chen, Sanxing; Huang, Yukun; Dhingra, Bhuwan (July 2025, Association for Computational Linguistics)

   We show that existing evaluations for assessing the factuality of news from conventional sources, such as claims on fact-checking websites, result in high accuracies over time for LLM-based detectors—even after their knowledge cutoffs. This suggests that recent popular false information from such sources can be easily identified due to its likely presence in pre-training/retrieval corpora or the emergence of salient, yet shallow, patterns in these datasets. Instead, we argue that a proper factuality evaluation dataset should test a model’s ability to reason about current events by retrieving and reading related evidence. To this end, we develop a novel pipeline that leverages natural language feedback from a RAG-based detector to iteratively modify real-time news into deceptive variants that challenge LLMs. Our iterative rewrite decreases the binary classification ROC-AUC by an absolute 17.5 percent for a strong RAG-based GPT-4o detector. Our experiments reveal the important role of RAG in both evaluating and generating challenging news examples, as retrieval-free LLM detectors are vulnerable to unseen events and adversarial attacks, while feedback from RAG-based evaluation helps discover more deceitful patterns. 

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4. Accelerating Retrieval-Augmented Generation

   https://doi.org/10.1145/3669940.3707264  

   Quinn, Derrick; Nouri, Mohammad; Patel, Neel; Salihu, John; Salemi, Alireza; Lee, Sukhan; Zamani, Hamed; Alian, Mohammad (March 2025, ACM)

   An evolving solution to address hallucination and enhance accuracy in large language models (LLMs) is Retrieval-Augmented Generation (RAG), which involves augmenting LLMs with information retrieved from an external knowledge source, such as the web. This paper profiles several RAG execution pipelines and demystifies the complex interplay between their retrieval and generation phases. We demonstrate that while exact retrieval schemes are expensive, they can reduce inference time compared to approximate retrieval variants because an exact retrieval model can send a smaller but more accurate list of documents to the generative model while maintaining the same end-to-end accuracy. This observation motivates the acceleration of the exact nearest neighbor search for RAG. In this work, we design Intelligent Knowledge Store (IKS), a type-2 CXL device that implements a scale-out near-memory acceleration architecture with a novel cache-coherent interface between the host CPU and near-memory accelerators. IKS offers 13.4--27.9× faster exact nearest neighbor search over a 512GB vector database compared with executing the search on Intel Sapphire Rapids CPUs. This higher search performance translates to 1.7--26.3× lower end-to-end inference time for representative RAG applications. IKS is inherently a memory expander; its internal DRAM can be disaggregated and used for other applications running on the server to prevent DRAM -- which is the most expensive component in today's servers -- from being stranded. 

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5. In-Storage Acceleration of Retrieval Augmented Generation as a Service

   https://doi.org/10.1145/3695053  

   Mahapatra, Rohan; Santhanam, Harsha; Priebe, Christopher; Xu, Hanyang; Esmaeilzadeh, Hadi (June 2025, Proceedings of the 52nd Annual International Symposium on Computer Architecture)

   Retrieval-augmented generation (RAG) services are rapidly gaining adoption in enterprise settings as they combine information retrieval systems (e.g., databases) with large language models (LLMs) to enhance response generation and reduce hallucinations. By augmenting an LLM’s fixed pre-trained knowledge with real-time information retrieval, RAG enables models to effectively extend their context to large knowledge bases by selectively retrieving only the most relevant information. As a result, RAG provides the effect of dynamic updates to the LLM’s knowledge without requiring expensive and time-consuming retraining. While some deployments keep the entire database in memory, RAG services are increasingly shifting toward persistent storage to accommodate ever-growing knowledge bases, enhance utility, and improve cost-efficiency. However, this transition fundamentally reshapes the system’s performance profile: empirical analysis reveals that the Search & Retrieval phase emerges as the dominant contributor to end-to-end latency. This phase typically involves (1) running a smaller language model to generate query embeddings, (2) executing similarity and relevance checks over varying data structures, and (3) performing frequent, long-latency accesses to persistent storage. To address this triad of challenges, we propose a metamorphic in-storage accelerator architecture that provides the necessary programmability to support diverse RAG algorithms, dynamic data structures, and varying computational patterns. The architecture also supports in-storage execution of smaller language models for query embedding generation while final LLM generation is executed on DGX A100 systems. Experimental results show up to 4.3 × and 1.5 × improvement in end-to-end throughput compared to conventional retrieval pipelines using Xeon CPUs with NVMe storage and A100 GPUs with DRAM, respectively. 

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