Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Baleen: Robust Multi-Hop Reasoning at Scale via Condensed Retrieval   Multi-hop reasoning (i.e., reasoning across two or more documents) is a key
ingredient for NLP models that leverage large corpora to exhibit broad
knowledge. To retrieve evidence passages, multi-hop models must contend with a
fast-growing search space across the hops, represent complex queries that
combine multiple information needs, and resolve ambiguity about the best order
in which to hop between training passages. We tackle these problems via Baleen,
a system that improves the accuracy and robustness of multi-hop retrieval. To
tame the search space, we propose condensed retrieval, a pipeline that
summarizes the retrieved passages after each hop into a single compact context.
To model complex queries, we introduce a focused late interaction retriever
that allows different parts of the same query representation to match disparate
relevant passages. Lastly, to infer the hopping dependencies among unordered
training passages, we devise latent hop ordering, a weak-supervision strategy
in which the trained retriever itself selects the sequence of hops. We evaluate
Baleen on retrieval for two-hop question answering and many-hop claim
verification, establishing state-of-the-art performance.

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The categories of this paper are: hep-lat
19
The categories of this paper are: eess
34
The categories of this paper are: chem-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: cond-mat
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The categories of this paper are: bayes-an
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The categories of this paper are: q-alg
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The categories of this paper are: patt-sol
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The categories of this paper are: funct-an
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The categories of this paper are: plasm-ph
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The categories of this paper are: q-bio
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The categories of this paper are: atom-ph
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The categories of this paper are: comp-gas
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The categories of this paper are: nucl-th
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The categories of this paper are: math
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The categories of this paper are: econ