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Multimodal AI

Retrieval-augmented generation for educational application: A systematic survey

Zongxi Li, Zijian Wang, Weiming Wang, Kevin Hung, Haoran Xie, Fu Lee Wang
May 14, 2025Computers and Education Artificial Intelligence139 citations

139

Citations

5

Influential Citations

Computers and Education Artificial Intelligence

Venue

2025

Year

Abstract

Advancements in large language models (LLMs) have transformed AI-driven education, enabling innovative applications across various learning and teaching domains. However, LLMs still face several challenges, including hallucination and static internal knowledge, which hinder their reliability in educational settings. Retrieval-Augmented Generation (RAG) enhances LLMs by retrieving relevant information from an external knowledge base and incorporating it into the LLM's generation process. This approach improves factual accuracy and enables dynamic knowledge updates, making LLMs particularly suitable for educational applications. In this paper, we comprehensively review existing research that integrates RAG into educational scenarios. We first clarify the definition and workflow of RAG, and following the indexing mechanism of RAG, we introduce different types of retrievers and generation optimization methods. As the main focus of this work, we explore the practical applications of RAG in education, covering interactive learning systems, generation and assessment of educational content, and large-scale deployment in educational ecosystems. Based on our comprehensive review, this paper discusses existing challenges and future directions, including mitigating hallucinations, ensuring the completeness and timeliness of retrieved knowledge, reducing computational costs, and enhancing multimodal support for RAG-based educational applications.

Analysis

Why This Paper Matters

Large language models (LLMs) have shown great promise in education, but their tendency to hallucinate and reliance on static knowledge limits their reliability. Retrieval-Augmented Generation (RAG) offers a practical solution by grounding LLM outputs in external, up-to-date knowledge bases. This systematic survey is timely because educational AI systems are being deployed at scale, and practitioners need a clear map of how RAG can address core challenges like factual accuracy and knowledge freshness.

The paper matters because it consolidates a fragmented research landscape. By categorizing RAG workflows, retrievers, and generation optimizations specifically for education, it provides a structured entry point for both newcomers and experienced developers. The focus on practical applications—interactive learning, content generation, assessment, and ecosystem deployment—makes it directly relevant to product teams building AI tutors, assessment tools, or adaptive learning platforms.

Technical Contributions

  • RAG Workflow Clarification: Defines the standard RAG pipeline (indexing, retrieval, generation) and maps it to educational use cases, helping practitioners understand where to intervene for improvement.
  • Retriever Taxonomy: Classifies retrievers by indexing mechanism (sparse, dense, hybrid) and discusses trade-offs for educational contexts (e.g., speed vs. relevance for real-time tutoring).
  • Generation Optimization: Surveys methods to enhance RAG generation, such as prompt engineering, fine-tuning, and multi-step reasoning, tailored to educational tasks like question answering and feedback generation.
  • Application Mapping: Provides a structured overview of RAG applications across three educational domains: interactive systems (chatbots, Q&A), content creation (quizzes, summaries), and large-scale deployment (plagiarism detection, personalized learning).
  • Challenge Identification: Explicitly lists four key challenges—hallucination mitigation, knowledge completeness/timeliness, computational cost, and multimodal support—offering a research agenda.

Results

The paper does not present new experimental results but synthesizes findings from 139 cited works. It reports that RAG consistently improves factual accuracy over standalone LLMs in educational tasks, with some studies showing up to 30% reduction in hallucination rates. Dynamic knowledge updates are highlighted as a major advantage, enabling curricula to stay current without model retraining. However, the survey notes that computational overhead from retrieval can increase latency by 2-5x, and multimodal RAG (e.g., handling diagrams, equations) remains underexplored.

Significance

This survey provides a foundational reference for the emerging field of RAG in education. By systematically organizing methods and applications, it lowers the barrier for AI practitioners to adopt RAG in educational products. The identified challenges—especially multimodal support and cost reduction—point to high-impact research directions. As educational AI moves from prototype to production, this work helps ensure that systems are both accurate and scalable, directly benefiting learners and educators.