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What is Hybrid Search?

Hybrid search is an information retrieval approach that combines traditional keyword-based search with modern semantic vector search, delivering more accurate and comprehensive results by matching both exact terms and conceptual meaning, making it the preferred method for enterprise AI and RAG systems.

What Is Hybrid Search?

Hybrid search is an approach to finding information that combines two fundamentally different search methods: traditional keyword search and modern semantic (vector) search. By blending both techniques, hybrid search delivers results that are both precisely relevant to the exact words used in a query and conceptually aligned with the searcher's intent.

To understand why this matters, consider a simple analogy. Imagine searching your company's document library for information about "staff turnover." A keyword search would find documents containing those exact words but miss a report titled "Employee Retention Challenges" that discusses the same topic without using the phrase "staff turnover." A semantic search would find both documents based on meaning but might also return loosely related results about "inventory turnover" or "asset rotation." Hybrid search combines the precision of keyword matching with the intelligence of semantic understanding, giving you the best of both worlds.

For businesses building AI-powered search, chatbots, or knowledge management systems, hybrid search has become the industry standard because neither keyword nor semantic search alone is sufficient for enterprise use cases.

How Hybrid Search Works

Hybrid search runs two parallel search processes and intelligently combines their results:

  • Keyword search (BM25 or similar): This traditional approach looks for exact or near-exact word matches in your documents. It excels at finding specific product names, codes, acronyms, and technical terms. When a user searches for "ISO 27001 compliance," keyword search reliably finds documents containing that exact standard reference.
  • Semantic search (vector search): This modern approach converts both the query and documents into numerical representations called vectors that capture meaning. It finds documents that are conceptually similar to the query even if they use different words. Searching for "how to protect customer data" would find documents about data security, privacy policies, and cybersecurity frameworks.
  • Result fusion: The results from both searches are combined using algorithms like Reciprocal Rank Fusion (RRF), which merges the two ranked lists into a single set of results that balances precision and semantic relevance. Each result gets a combined score based on its ranking in both searches.

Most modern vector databases, including Weaviate, Pinecone, Qdrant, and Elasticsearch, now offer built-in hybrid search capabilities. This means implementing hybrid search does not require building two separate systems.

Why Hybrid Search Matters for Business

For business leaders investing in AI systems that need to search over company data, hybrid search solves real problems that directly affect the return on your AI investment:

  • Eliminates the keyword gap. Pure semantic search often struggles with specific identifiers like product codes, policy numbers, legal citations, or technical acronyms. In a region as diverse as Southeast Asia, where business documents mix English with local language terms, brand names, and regulatory references, keyword matching is essential for precision.
  • Eliminates the vocabulary gap. Pure keyword search fails when users phrase questions differently from how information is stored. If your HR policy documents use "remuneration" but employees search for "salary" or "pay," keyword search returns nothing. Semantic search bridges this vocabulary mismatch.
  • Higher retrieval accuracy for RAG systems. In retrieval-augmented generation systems that power AI chatbots and assistants, the quality of retrieved documents directly determines the quality of AI responses. Studies consistently show that hybrid search retrieves more relevant documents than either method alone, leading to better AI outputs.
  • Handles diverse query types. Business users ask questions in many ways, from precise lookups like "Q3 2025 revenue Singapore" to exploratory questions like "what are our biggest competitive risks in Indonesia." Hybrid search handles both effectively.

Key Examples and Use Cases

Enterprise knowledge management. A professional services firm in Singapore deployed hybrid search across their internal knowledge base of project reports, methodologies, and client deliverables. Consultants could search using either specific project codes and client names (handled by keyword search) or conceptual queries about industry challenges and approaches (handled by semantic search). The firm reported that consultants found relevant past work 60 percent faster compared to their previous keyword-only search system.

E-commerce product search. Platforms like Shopee and Lazada serve customers across Southeast Asia who search for products using a mix of exact product names, brand terms, and descriptive language. Hybrid search ensures that a query for "Samsung Galaxy screen protector" finds exact product matches while also surfacing compatible alternatives described as "phone screen guard" or "tempered glass for Galaxy series."

Regulatory and compliance search. Banks and financial institutions operating across ASEAN markets maintain large repositories of regulatory documents. Compliance officers need to find specific regulations by number or name (keyword search) and also discover related regulations that address similar topics in different jurisdictions (semantic search). Hybrid search serves both needs in a single query.

Customer support automation. Gojek and similar super-apps with millions of users need AI-powered support systems that can handle questions ranging from "what is the refund policy for GoPay" (specific, keyword-oriented) to "I was charged twice for a ride that was cancelled" (contextual, requiring semantic understanding). Hybrid search ensures the AI retrieves the most relevant help articles regardless of how the customer phrases their question.

Getting Started with Hybrid Search

Implementing hybrid search is straightforward with modern tools. Here is a practical path:

  1. Choose a vector database with built-in hybrid search. Weaviate, Pinecone, Qdrant, and Elasticsearch all support hybrid search natively. This eliminates the need to build and maintain two separate search systems.
  2. Index your documents for both methods. Each document needs both a text index for keyword search and a vector embedding for semantic search. Most modern indexing pipelines handle this automatically.
  3. Tune the balance between keyword and semantic results. Most hybrid search implementations let you set a weight parameter, typically called alpha, that controls how much influence each search method has on the final results. Start with equal weighting and adjust based on your testing.
  4. Test with representative queries. Create a test set that includes both precise lookups and conceptual questions. Measure whether hybrid search outperforms either method alone for your specific data and use cases.
  5. Monitor and iterate. Track which queries produce poor results and use that information to refine your indexing, chunking, and fusion parameters over time.

Hybrid search has rapidly become the default approach for enterprise AI search because it robustly handles the full range of queries business users generate. For any organisation building RAG-based AI applications, implementing hybrid search is one of the most impactful improvements you can make.

Why It Matters for Business

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Key Considerations
  • Hybrid search is now the industry standard for enterprise AI search systems. If your RAG or AI search implementation uses only keyword or only semantic search, you are likely leaving significant accuracy improvements on the table.
  • Most modern vector databases offer built-in hybrid search, so implementation does not require building two separate systems. Evaluate your current database vendor's hybrid search capabilities before considering migration.
  • The balance between keyword and semantic search weighting should be tuned for your specific data and use cases. Plan for an iterative testing phase where you optimise this parameter using real user queries and feedback.

Frequently Asked Questions

Is hybrid search more expensive than using one search method?

Hybrid search does require slightly more computing resources since it runs two search processes in parallel and then combines the results. However, the additional cost is modest, typically 20-40 percent more than a single search method, and well-justified by the significant improvement in result quality. Most businesses find that the cost of poor search results, in terms of wasted employee time and lower AI accuracy, far exceeds the incremental infrastructure cost of hybrid search.

Can hybrid search work with documents in multiple languages?

Yes, and this is one of the areas where hybrid search particularly excels. The keyword component handles language-specific terms, brand names, and identifiers that should match exactly regardless of language. The semantic component, when using multilingual embedding models, can find conceptually similar content across languages. This is especially valuable for businesses operating across ASEAN markets with documents in English, Bahasa, Thai, Vietnamese, and other regional languages.

More Questions

The most practical approach is to create a test set of 50-100 representative queries with known relevant documents, then compare the results from keyword-only search, semantic-only search, and hybrid search. Measure metrics like precision at the top five results and recall across the full result set. Most organisations see a 15-30 percent improvement in retrieval accuracy with hybrid search compared to either method alone. You can also measure indirectly by tracking user satisfaction with AI-generated answers before and after implementing hybrid search.

Need help implementing Hybrid Search?

Pertama Partners helps businesses across Southeast Asia adopt AI strategically. Let's discuss how hybrid search fits into your AI roadmap.