iterative retrieval
**Iterative retrieval** is the **retrieval strategy that repeatedly refines queries and candidate selection based on intermediate findings** - it improves evidence quality when initial retrieval is incomplete or noisy.
**What Is Iterative retrieval?**
- **Definition**: Multi-round retrieval loop where each round uses context from previous rounds.
- **Refinement Signals**: Uses partial answers, uncertainty cues, or missing-entity detection.
- **Stopping Criteria**: Terminates on confidence threshold, max rounds, or saturation of new evidence.
- **Pipeline Role**: Bridges retrieval and reasoning for hard information needs.
**Why Iterative retrieval Matters**
- **Coverage Recovery**: Second or third rounds can find evidence missed by first-pass queries.
- **Noise Reduction**: Later rounds can focus search space using validated intermediate facts.
- **Answer Robustness**: Progressive refinement lowers chance of premature incorrect conclusions.
- **Adaptivity**: System reacts dynamically to ambiguous or under-specified user input.
- **Practical Accuracy**: Often improves outcomes on long-tail and multi-step questions.
**How It Is Used in Practice**
- **Loop Controller**: Track evidence gain and confidence at each retrieval iteration.
- **Query Rewriter**: Generate focused follow-up queries from unresolved sub-questions.
- **Budget Governance**: Cap rounds and compute usage to preserve latency objectives.
Iterative retrieval is **a useful strategy for hard-query evidence discovery** - iterative loops trade modest extra compute for stronger retrieval completeness and answer reliability.