How can I determine the optimal weight balance between keyword and semantic search in my hybrid RAG pipeline?

Start with α = 0.5 (equal weighting) as your baseline, then adjust based on your query patterns and content type. Monitor these signals from production:

If users complain about missing exact matches they know exist → decrease α (favor keywords more) If results are too literal and miss conceptually related content → increase α (favor semantics more) For legal/medical/technical documentation where precision matters → use α = 0.3-0.4 For conversational/support content where intent matters more than exact wording → use α = 0.6-0.7

Pro tip: Implement A/B testing with different α values for different query types - short queries often benefit from higher semantic weight while longer, specific queries need more keyword emphasis.