Before revision:  Baleen introduces a per-hop condensed retrievalpipeline to mitigate the size of the search space, a focused late interaction retriever (FliBERT) that can model complex multi-hop queries, and a weak supervision strategy, latent hop ordering, to learn from limited signal about which documents to retrieve for a query .
After revision:  Baleen introduces a per-hop condensed retrievalpipeline to mitigate the size of the search space, a focused late interaction retriever (FliBERT) that can model complex multi-hop queries, and a weak supervision strategy, latent hop ordering, a weak-supervision strategy in which the trained retriever itself selects the sequence of hops .