hotpotqa

**HotpotQA** is a **multi-hop question answering dataset requiring reasoning across multiple documents to find the answer** — questions are explicitly designed to be unanswerable from a single paragraph, forcing the model to "hop" from one fact to another. **Structure** - **Bridge**: Q: "What award did the instigator of the 1906 San Francisco earthquake win?" - **Hop 1**: Find "1906 earthquake instigator" $ o$ "The earthquake was not 'instigated' but..." (Bad example). - **Real Example**: "Who played the wife of the actor who played Bond in GoldenEye?" (Hop 1: Bond in GoldenEye $ o$ Pierce Brosnan. Hop 2: Wife of Pierce Brosnan). - **Explainability**: Models must output the "supporting facts" sentences used to reach the conclusion. **Why It Matters** - **Reasoning**: Breaks simple "keyword matching" QA. - **Retrieval**: Requires iterative or multi-step retrieval (Retrieve Doc A $ o$ Extract Entity $ o$ Retrieve Doc B). **HotpotQA** is **connect-the-facts** — enforcing multi-step reasoning chains where finding the answer requires synthesizing information from disparate sources.