Let Me Explain - Knowledge-Based Retrieval Augmented Generation for Agricultural Recommendation Explanations
摘要
Recommender systems play an important role in providing items to users that align with their goals. However, explaining the relevance of recommended items remains challenging; a particularly important task for high-stakes domains like agriculture where both suitability and interpretability of recommendations is crucial. Knowledge Graph (KG)-based approaches can provide suitable recommendations, but lack fluent explanations. Recent Large Language Model (LLM)-based recommender systems excel in natural explanations, yet are limited in factuality or coherence. Combining strengths of LLM-based recommendations with knowledge presents a promising direction. We introduce KRAGGER (Knowledge Retrieval-Augmented Generation for Graph-based Explainable Recommendation), a composite framework combining KG- and LLM-based methods. We apply KRAGGER to an agricultural use case by testing its ability to recommend technologies to farmers while explaining provided matches. The contributions of this paper are: 1) KRAGGER’s three recommendation methods: Graph-Graph, Graph-Attribute and Attribute-Attribute matching, and 2) KRAGGER’s three explanation methods: Rule-Based (RB), LLM and RB-LLM, and 3) an agricultural recommendation KG dataset describing farmers and farm technologies. Recommendation performance of KRAGGER is measured quantitatively with catalog coverage and intra-list diversity on five different embedding models. Additionally, a user study is performed with domain experts to validate recommendation performance and measure simplicity, fluency, coherence and trustworthiness of explanations. Results show the fine-grained attribute matching recommendation performs best, which forms the basis of the highest rated RB-LLM rephrasing explanation method. Thus, KRAGGER shows promising capabilities for grounded, yet natural recommendation explanations, underscoring the importance of composite AI (KGs and LLMs) to support difficult decision making.