A Survey on Knowledge Graphs: Representation, Acquisition, and Applications
Shaoxiong JiShirui PanErik CambriaPekka MarttinenPhilip S. Yu
Systematizes knowledge graph research through a structured taxonomy spanning representation learning, automated knowledge acquisition, and real-world applications while highlighting key open-source resources and future research directions.
Knowledge graphs represent structured facts about entities and their relationships, enabling artificial intelligence systems to perform reasoning tasks that mimic aspects of human cognition. The field has grown rapidly since Google’s 2012 launch of its Knowledge Graph, yet research remains scattered across representation techniques, data acquisition methods, temporal modeling, and downstream uses, making it difficult for practitioners to identify the most effective approaches or spot gaps.
This survey set out to deliver a single, structured overview of the entire knowledge-graph literature, introducing consistent taxonomies for representation learning, completion and extraction tasks, temporal extensions, and real-world applications while cataloguing datasets and open-source tools.
The authors reviewed several hundred papers published through early 2021, grouping methods according to their mathematical foundations (vector spaces, complex numbers, manifolds, Gaussian distributions), scoring functions (distance-based versus similarity-based), encoding architectures (linear, bilinear, convolutional, recurrent, graph neural, and transformer-based), and use of auxiliary signals such as text or images. They applied the same systematic lens to knowledge-graph completion via embeddings, path reasoning, and logical rules; to entity and relation discovery from text; and to temporal and application-oriented work.
The review shows that embedding models have matured from simple translation-based approaches to expressive architectures that capture symmetry, hierarchy, and uncertainty, yet they still struggle with long-range logical inference. Hybrid systems that combine embeddings with explicit rules or reinforcement-learned paths improve both accuracy and interpretability. Neural encoders now dominate relation extraction, while graph-aware language models and path-reasoning agents are beginning to deliver measurable gains on question answering and recommendation tasks. A curated collection of benchmark datasets and libraries is provided to lower the barrier for new experiments.
These findings matter because knowledge graphs underpin search engines, conversational agents, drug-discovery platforms, and enterprise data integration; clearer maps of what works reduce duplicated effort and speed deployment of reliable systems. The survey also highlights open challenges—scalable complex reasoning, unified frameworks that treat text and graphs together, interpretability, and automatic maintenance of evolving graphs—that must be addressed before knowledge-graph technology can support robust, large-scale cognitive applications.
- Paper: Translating Embeddings for Modeling Multi-relational Data, Antoine Bordes et al. (2013). Translating Embeddings for Modeling Multi-relational Data introduces TransE, the foundational translation-based knowledge graph embedding model heavily analyzed in the source survey.
- Paper: Knowledge Graph Embedding by Translating on Hyperplanes, Zhen Wang et al. (2014). Knowledge Graph Embedding by Translating on Hyperplanes presents TransH, directly establishing the foundational hyperplane-translation approach reviewed in the source's representation section.
- Paper: Modeling Relational Data with Graph Convolutional Networks, Michael Schlichtkrull et al. (2018). Modeling Relational Data with Graph Convolutional Networks introduces R-GCNs, the primary network architecture detailed in the source survey for knowledge graph completion and link prediction.
- Paper: A Comprehensive Survey on Graph Neural Networks, Zonghan Wu et al. (2019). A Comprehensive Survey on Graph Neural Networks establishes the broader graph deep learning foundations that the source survey builds upon when analyzing graph-based representation learning.
- Paper: Retrieval-Augmented Generation for Large Language Models: A Survey, Yunfan Gao et al. (2023). Retrieval-Augmented Generation for Large Language Models: A Survey extends the source survey by exploring how modern knowledge-intensive architectures integrate external knowledge graphs and retrieval systems.
