Evaluating Network Embeddings Through the Lens of Community Structure

Network embedding, a technique that transforms the nodes and edges of a network into low-dimensional vector representations while preserving relevant structural and semantic information, has gained prominence in recent years. Community structure is one of the most prevalent features of networks, and ensuring its preservation is crucial to represent the network in a lower-dimensional space accurately. While the core objective of network embedding is to bring related nodes in the original network close together in a lower-dimensional space, common classification metrics overlook community structure preservation. This work addresses the need for a comprehensive analysis of network embedding algorithms at the community level. On a set of synthetic networks that span strong to weak community structure strengths, we showcase the variability in the performance of network embedding techniques across mesoscopic metrics. Additionally, we highlight that the mesoscopic metrics are not highly correlated with the classification metrics. The community structure can further diminish the correlation as its strength weakens.