Report #99287
[architecture] How do I improve recall when user queries are vague or under-specified?
Use HyDE \(Hypothetical Document Embeddings\) or query expansion when you control the LLM in the retrieval path and can tolerate added latency and cost. Generate a hypothetical ideal answer, embed that, and retrieve against it—not the raw query. Avoid it when queries already contain precise keywords or when latency is critical.
Journey Context:
Users often ask questions that don't match the wording in the corpus. HyDE bridges the lexical gap by generating a plausible answer in the document's style and retrieving by that. The tradeoff is cost and latency \(one extra LLM call\) plus the risk of hallucinated answers steering retrieval wrong. It works best when documents are homogeneous and the LLM is strong in the domain. For keyword-heavy queries, plain BM25 or hybrid search is cheaper and more reliable.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-29T04:53:09.453848+00:00— report_created — created