What are the use cases of knowledge graphs?

Knowledge graphs are structured databases that represent entities (like people, places, or concepts) and their relationships in a way that machines can process. They are particularly useful in scenarios where understanding connections between data points is critical. Three key use cases include enhancing search capabilities, integrating heterogeneous data sources, and powering recommendation systems.

First, knowledge graphs improve search engines by enabling semantic search. Traditional keyword-based search often struggles with ambiguous terms or context. For example, a search for “Apple” could refer to the company, the fruit, or a record label. A knowledge graph resolves this by linking the term to related entities (e.g., “Apple Inc.” connected to “Steve Jobs” or “iPhone”). Google uses this approach in its Knowledge Panel to provide direct answers and contextual links. Developers can implement similar systems using tools like Apache Jena or AWS Neptune, which allow querying connected data via SPARQL or GraphQL interfaces. This capability is especially valuable in domains like healthcare, where a search for a disease might need to surface symptoms, treatments, and related research papers.

Second, knowledge graphs help integrate disparate data sources. Organizations often store data in silos—CRM systems, product databases, and external APIs—that don’t natively connect. A knowledge graph can map relationships across these sources. For instance, an e-commerce company might link customer profiles (from a CRM) to purchase histories (from a transactional database) and product details (from a catalog) to create a unified view. This integration supports applications like supply chain optimization, where understanding how supplier delays affect inventory requires combining logistics, vendor, and sales data. Tools like Neo4j or Amazon Neptune simplify building such graphs by providing scalable storage and traversal capabilities for connected data.

Third, recommendation systems leverage knowledge graphs to deliver personalized suggestions. By modeling user preferences, product attributes, and behavioral patterns as interconnected nodes, these systems can identify non-obvious relationships. For example, a streaming service might recommend a documentary about space exploration to a user who watches sci-fi movies, based on shared themes like “astronomy” or “technology.” Similarly, in fraud detection, banks analyze transaction patterns as a graph to spot suspicious connections between accounts. Frameworks like TensorFlow GNN or PyTorch Geometric enable developers to build graph-based machine learning models for such tasks. These systems excel in scenarios where linear data models (like relational databases) fail to capture complex interdependencies.