Link Prediction in Complex Networks: A Survey
Linyuan LuTao Zhou
Systematizes link prediction methods across statistical physics and computer science, providing actionable algorithms for reconstructing missing connections and testing network evolution models.
The article addresses the challenge of predicting missing or future links in complex networks that represent social, biological, and information systems, where incomplete or noisy data hinders analysis of structure and function. This task matters now because accurate predictions can sharply cut experimental costs in areas like protein interactions while enabling better recommendations and mechanism evaluation in evolving networks. The article set out to survey recent link prediction algorithms, with emphasis on physical approaches such as random-walk-based methods and maximum likelihood estimation, while also covering applications and open challenges. It reviews the methods through classification into similarity-based indices, maximum likelihood techniques, and probabilistic models, then evaluates them on real networks using standard metrics of AUC and precision across training and probe sets obtained by random or cross-validation splits. Key findings show that local indices such as resource allocation outperform common-neighbor and preferential-attachment measures on most tested networks, quasi-local indices like the local-path method deliver competitive accuracy at far lower cost than global measures, Katz and random-walk-with-restart indices achieve the highest overall accuracy when full topology is available, and maximum-likelihood methods based on hierarchical or stochastic block models provide valuable structural insight even if they are slower and sometimes less accurate. These results indicate that algorithm choice should match network features such as clustering and average distance, directly affecting practical outcomes in cost reduction, network reconstruction, and model selection. The survey recommends developing hybrid ensemble predictors, extending methods to directed, weighted, and multi-dimensional networks, and incorporating temporal information and node attributes for better performance on dynamic or sparsely labeled data; additional work is required before strong decisions can be made on very large or rapidly changing systems. The main limitations are the focus on undirected unweighted networks and the dependence of relative performance on specific structural properties, so readers should treat the reported rankings as indicative rather than universal.
- Paper: The link prediction problem for social networks, David Liben-Nowell et al. (2003). This seminal paper formalized the topological link prediction problem and established the benchmark node proximity heuristics evaluated throughout the survey.
- Paper: Hierarchical structure and the prediction of missing links in networks, Aaron Clauset et al. (2008). It introduces the hierarchical random graph and maximum likelihood estimation framework for predicting missing links, which forms a primary category of algorithms in the survey.
- Paper: SimRank: a measure of structural-context similarity, Glen Jeh et al. (2002). It defines SimRank, a foundational global structural-context similarity metric based on random walks that is analyzed and compared in the survey.
- Paper: Markov logic networks, Matthew Richardson et al. (2006). It establishes Markov logic networks, providing the core theoretical foundation for the probabilistic and relational modeling approaches reviewed in the survey.
- Paper: Community detection in graphs, Santo Fortunato (2009). It provides a comprehensive treatment of community structure and graph partitioning, which underpins the block modeling and community-based link prediction methods examined in the survey.
- Paper: Graphs over time: densification laws, shrinking diameters and possible explanations, J. Leskovec et al. (2005). It analyzes network evolution and densification patterns over time, providing empirical context for the dynamic and evolving network predictions surveyed.
- Paper: Link Prediction Based on Graph Neural Networks, Muhan Zhang et al. (2018). It extends classical heuristic-based link prediction into modern deep learning by proving that high-order heuristics can be learned from enclosing subgraphs using graph neural networks.
- Paper: Variational Graph Auto-Encoders, Thomas N. Kipf et al. (2016). It develops variational graph auto-encoders, formulating an unsupervised deep learning paradigm for link prediction that integrates both topology and node features.
- Paper: node2vec: Scalable Feature Learning for Networks, Aditya Grover et al. (2016). It generalizes similarity and random-walk concepts to learn continuous node representations specifically optimized for downstream edge prediction.
- Paper: A Three-Way Model for Collective Learning on Multi-Relational Data, Maximilian Nickel et al. (2011). It directly addresses the survey's call for link prediction on multi-relational graphs by formulating a scalable tensor factorization framework.
- Paper: Modeling Relational Data with Graph Convolutional Networks, Michael Schlichtkrull et al. (2018). It advances link prediction to directed, multi-relational knowledge graphs using relational graph convolutional networks.
- Paper: DeepWalk: online learning of social representations, Bryan Perozzi et al. (2014). It pioneers representation learning on graphs via random walks, transitioning network link analysis from explicit similarity metrics to continuous vector embeddings.
- Paper: Structural Deep Network Embedding, Daixin Wang et al. (2016). It applies deep autoencoders to preserve both first-order and second-order network proximity for enhanced link reconstruction in sparse graphs.
- Paper: Temporal Networks, Petter Holme et al. (2011). It expands link analysis into dynamic temporal systems, addressing the challenge highlighted in the survey regarding time-respecting paths and evolving contacts.
- Paper: The structure and dynamics of multilayer networks, S. Boccaletti et al. (2014). It generalizes structural measures and connection dynamics to multilayer and multiplex networks, fulfilling a key future direction identified by the survey.
- Paper: Neural Graph Collaborative Filtering, Xiang Wang et al. (2019). It applies graph convolutional message passing to bipartite user-item interaction graphs for high-order collaborative filtering and link recommendation.
