Emergent Mind

DiffKG: Knowledge Graph Diffusion Model for Recommendation

(2312.16890)
Published Dec 28, 2023 in cs.IR

Abstract

Knowledge Graphs (KGs) have emerged as invaluable resources for enriching recommendation systems by providing a wealth of factual information and capturing semantic relationships among items. Leveraging KGs can significantly enhance recommendation performance. However, not all relations within a KG are equally relevant or beneficial for the target recommendation task. In fact, certain item-entity connections may introduce noise or lack informative value, thus potentially misleading our understanding of user preferences. To bridge this research gap, we propose a novel knowledge graph diffusion model for recommendation, referred to as DiffKG. Our framework integrates a generative diffusion model with a data augmentation paradigm, enabling robust knowledge graph representation learning. This integration facilitates a better alignment between knowledge-aware item semantics and collaborative relation modeling. Moreover, we introduce a collaborative knowledge graph convolution mechanism that incorporates collaborative signals reflecting user-item interaction patterns, guiding the knowledge graph diffusion process. We conduct extensive experiments on three publicly available datasets, consistently demonstrating the superiority of our DiffKG compared to various competitive baselines. We provide the source code repository of our proposed DiffKG model at the following link: https://github.com/HKUDS/DiffKG.

Overview

  • DiffKG introduces a knowledge-aware recommendation system that enhances recommendation quality by refining KG representations using generative diffusion models.

  • The framework significantly improves recommendation systems by filtering out irrelevant information in KGs and focusing on pertinent entity relationships.

  • DiffKG's comprehensive evaluation across multiple domains shows its superiority over established baselines, especially in tackling data sparsity and noise.

  • The study suggests future research directions for further enhancing recommendation systems through the integration of diffusion models and KGs, including aspects like dynamic KGs and interpretability of recommendations.

Introducing DiffKG: Enhancing Recommendation Systems through Knowledge Graph Diffusion Models

Knowledge-aware Recommendation Enhanced by Diffusion Models

The field of recommendation systems has witnessed rapid advancements, spearheaded by the integration of knowledge graphs (KGs) to tackle the perpetual challenge of sparse user-item interactions. In this paper, we introduce the DiffKG framework, a novel approach that harnesses the power of generative diffusion models to refine knowledge graph (KG) representations for the specific task of recommendation. This technique addresses the critical issue of noise and irrelevant information in KGs, which can adversely affect recommendation quality.

Key Innovations of DiffKG

The DiffKG framework is distinguished by three pivotal contributions to the domain of knowledge-aware recommendation systems:

  1. Task-Specific Knowledge Graph Optimization: Unlike conventional methods that utilize KGs as-is, the DiffKG model applies a diffusion process to iteratively corrupt and reconstruct the KG. This process effectively filters out irrelevant entity relationships, preserving only those that are pertinent to the recommendation task.
  2. Generative Diffusion Model Integration: At its core, the DiffKG utilizes a generative diffusion paradigm to iteratively model the distribution of relevant KG relationships. This innovative step enables the encoding of user preferences more accurately by ensuring that only task-relevant KG information is considered in the recommendation process.
  3. Collaborative Knowledge Convolution Mechanism: To further align the revised KG with user-item interaction patterns, DiffKG introduces a collaborative knowledge graph convolution (CKGC) mechanism. This component enhances the KG diffusion process with collaborative signals, ensuring the distilled KG is optimally aligned with the underlying recommendation tasks.

Comprehensive Evaluation and Insights

Extensive experiments conducted on public datasets across various domains (music, news, e-commerce) validate the superiority of DiffKG over established baselines, including both traditional collaborative filtering models and contemporary KG-enhanced recommenders. These results underscore the framework's capability to effectively mitigate the impacts of data sparsity and noise, two prevalent challenges in recommendation systems.

Addressing Data Sparsity and Noise

The evaluation particularly highlights DiffKG's adeptness at navigating the realm of sparse user interaction data and noisy KG inputs. By generating task-specific KGs that seamlessly integrate with collaborative filtering processes, DiffKG exhibits remarkable resilience against these pervasive issues, offering refined and relevant recommendations even under challenging conditions.

Future Directions

The promising outcomes of this study pave the way for further exploration into the synergistic potential of diffusion models and KGs in enhancing recommendation systems. Future research could delve into optimizing the diffusion process for dynamic KGs or extending the framework to incorporate temporal dynamics in user-item interactions. Another intriguing avenue involves investigating the interpretability of recommendations provided by DiffKG, offering insights into the decision-making process and the role of KG relations in shaping user preference modeling.

Concluding Remarks

DiffKG stands out as a significant stride forward in the evolution of knowledge-aware recommendation systems. By judiciously integrating generative diffusion models with knowledge graph learning, the framework sets a new benchmark in addressing data quality challenges prevalent in recommendation scenarios. As we move forward, the principles and methodologies underscored by DiffKG will undoubtedly inspire further innovations, pushing the boundaries of personalized recommendation systems.

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