{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2020:73C5AUK4J5PTQ5QNAHPFXU4DZV","short_pith_number":"pith:73C5AUK4","canonical_record":{"source":{"id":"2009.08956","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IR","submitted_at":"2020-09-01T16:52:51Z","cross_cats_sorted":["cs.LG","stat.ML"],"title_canon_sha256":"8ef1c60bc56ccf27e24ca885f399c26a8ad5b14f12ed0995c9bfa46e6acdf41c","abstract_canon_sha256":"3a4406fdbed0498e8c4a1a31b9fb176f36bce975deb1bd80a7d4ecfbe165547f"},"schema_version":"1.0"},"canonical_sha256":"fec5d0515c4f5f38760d01de5bd383cd435240d3f1b07eb32f451189ae5c5f09","source":{"kind":"arxiv","id":"2009.08956","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2009.08956","created_at":"2026-07-05T01:36:24Z"},{"alias_kind":"arxiv_version","alias_value":"2009.08956v1","created_at":"2026-07-05T01:36:24Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2009.08956","created_at":"2026-07-05T01:36:24Z"},{"alias_kind":"pith_short_12","alias_value":"73C5AUK4J5PT","created_at":"2026-07-05T01:36:24Z"},{"alias_kind":"pith_short_16","alias_value":"73C5AUK4J5PTQ5QN","created_at":"2026-07-05T01:36:24Z"},{"alias_kind":"pith_short_8","alias_value":"73C5AUK4","created_at":"2026-07-05T01:36:24Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2020:73C5AUK4J5PTQ5QNAHPFXU4DZV","target":"record","payload":{"canonical_record":{"source":{"id":"2009.08956","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IR","submitted_at":"2020-09-01T16:52:51Z","cross_cats_sorted":["cs.LG","stat.ML"],"title_canon_sha256":"8ef1c60bc56ccf27e24ca885f399c26a8ad5b14f12ed0995c9bfa46e6acdf41c","abstract_canon_sha256":"3a4406fdbed0498e8c4a1a31b9fb176f36bce975deb1bd80a7d4ecfbe165547f"},"schema_version":"1.0"},"canonical_sha256":"fec5d0515c4f5f38760d01de5bd383cd435240d3f1b07eb32f451189ae5c5f09","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T01:36:24.068556Z","signature_b64":"quabE3/R2kvKIytsjDPYI654QGmSoEEBkx1NRqJwViAbjKC11f+T7GP+lfx7AKQ4i8Xr+xeRhgN9rSSlspNJDg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"fec5d0515c4f5f38760d01de5bd383cd435240d3f1b07eb32f451189ae5c5f09","last_reissued_at":"2026-07-05T01:36:24.068163Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T01:36:24.068163Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2009.08956","source_version":1,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-07-05T01:36:24Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"cNpHnCR+BT7Zq6Zbgrq8mNlIt9b5tLnbxPl2OwFlG1LKuIrwfcA4mqpqcQPUMHovIvXXx3pRgJTOyAYbEWE6CA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-24T00:30:02.196900Z"},"content_sha256":"244d891cddd751b821aae0de923eb7c18e230b44973180fe2a6707624e286d00","schema_version":"1.0","event_id":"sha256:244d891cddd751b821aae0de923eb7c18e230b44973180fe2a6707624e286d00"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2020:73C5AUK4J5PTQ5QNAHPFXU4DZV","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Exploration in two-stage recommender systems","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["cs.LG","stat.ML"],"primary_cat":"cs.IR","authors_text":"Jiri Hron, Karl Krauth, Michael I. Jordan, Niki Kilbertus","submitted_at":"2020-09-01T16:52:51Z","abstract_excerpt":"Two-stage recommender systems are widely adopted in industry due to their scalability and maintainability. These systems produce recommendations in two steps: (i) multiple nominators preselect a small number of items from a large pool using cheap-to-compute item embeddings; (ii) with a richer set of features, a ranker rearranges the nominated items and serves them to the user. A key challenge of this setup is that optimal performance of each stage in isolation does not imply optimal global performance. In response to this issue, Ma et al. (2020) proposed a nominator training objective importan"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2009.08956","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2009.08956/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"},"verdict_id":null},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-07-05T01:36:24Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"/XLxgAyjN2fhaKUpBIzvpy6aDMzAVFvMYrGvenZPzw0eUulDY/WFFMHsjyKqU+xKXkUl5BvXSHW7v06CO03DCg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-24T00:30:02.197407Z"},"content_sha256":"9f8ca72b435838b1e85c3bec0d7c008a483485eac2df4b75f73dbb9168fd4b62","schema_version":"1.0","event_id":"sha256:9f8ca72b435838b1e85c3bec0d7c008a483485eac2df4b75f73dbb9168fd4b62"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/73C5AUK4J5PTQ5QNAHPFXU4DZV/bundle.json","state_url":"https://pith.science/pith/73C5AUK4J5PTQ5QNAHPFXU4DZV/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/73C5AUK4J5PTQ5QNAHPFXU4DZV/bundle.json","status":"primary"}],"public_keys":[{"key_id":"pith-v1-2026-05","algorithm":"ed25519","format":"raw","public_key_b64":"stVStoiQhXFxp4s2pdzPNoqVNBMojDU/fJ2db5S3CbM=","public_key_hex":"b2d552b68890857171a78b36a5dccf368a953413288c353f7c9d9d6f94b709b3","fingerprint_sha256_b32_first128bits":"RVFV5Z2OI2J3ZUO7ERDEBCYNKS","fingerprint_sha256_hex":"8d4b5ee74e4693bcd1df2446408b0d54","rotates_at":null,"url":"https://pith.science/pith-signing-key.json","notes":"Pith uses this Ed25519 key to sign canonical record SHA-256 digests. Verify with: ed25519_verify(public_key, message=canonical_sha256_bytes, signature=base64decode(signature_b64))."}],"merge_version":"pith-open-graph-merge-v1","built_at":"2026-08-24T00:30:02Z","links":{"resolver":"https://pith.science/pith/73C5AUK4J5PTQ5QNAHPFXU4DZV","bundle":"https://pith.science/pith/73C5AUK4J5PTQ5QNAHPFXU4DZV/bundle.json","state":"https://pith.science/pith/73C5AUK4J5PTQ5QNAHPFXU4DZV/state.json","well_known_bundle":"https://pith.science/.well-known/pith/73C5AUK4J5PTQ5QNAHPFXU4DZV/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2020:73C5AUK4J5PTQ5QNAHPFXU4DZV","merge_version":"pith-open-graph-merge-v1","event_count":2,"valid_event_count":2,"invalid_event_count":0,"equivocation_count":0,"current":{"canonical_record":{"metadata":{"abstract_canon_sha256":"3a4406fdbed0498e8c4a1a31b9fb176f36bce975deb1bd80a7d4ecfbe165547f","cross_cats_sorted":["cs.LG","stat.ML"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IR","submitted_at":"2020-09-01T16:52:51Z","title_canon_sha256":"8ef1c60bc56ccf27e24ca885f399c26a8ad5b14f12ed0995c9bfa46e6acdf41c"},"schema_version":"1.0","source":{"id":"2009.08956","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2009.08956","created_at":"2026-07-05T01:36:24Z"},{"alias_kind":"arxiv_version","alias_value":"2009.08956v1","created_at":"2026-07-05T01:36:24Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2009.08956","created_at":"2026-07-05T01:36:24Z"},{"alias_kind":"pith_short_12","alias_value":"73C5AUK4J5PT","created_at":"2026-07-05T01:36:24Z"},{"alias_kind":"pith_short_16","alias_value":"73C5AUK4J5PTQ5QN","created_at":"2026-07-05T01:36:24Z"},{"alias_kind":"pith_short_8","alias_value":"73C5AUK4","created_at":"2026-07-05T01:36:24Z"}],"graph_snapshots":[{"event_id":"sha256:9f8ca72b435838b1e85c3bec0d7c008a483485eac2df4b75f73dbb9168fd4b62","target":"graph","created_at":"2026-07-05T01:36:24Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"graph_snapshot":{"author_claims":{"count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","strong_count":0},"builder_version":"pith-number-builder-2026-05-17-v1","claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"integrity":{"available":true,"clean":true,"detectors_run":[],"endpoint":"/pith/2009.08956/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"Two-stage recommender systems are widely adopted in industry due to their scalability and maintainability. These systems produce recommendations in two steps: (i) multiple nominators preselect a small number of items from a large pool using cheap-to-compute item embeddings; (ii) with a richer set of features, a ranker rearranges the nominated items and serves them to the user. A key challenge of this setup is that optimal performance of each stage in isolation does not imply optimal global performance. In response to this issue, Ma et al. (2020) proposed a nominator training objective importan","authors_text":"Jiri Hron, Karl Krauth, Michael I. Jordan, Niki Kilbertus","cross_cats":["cs.LG","stat.ML"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IR","submitted_at":"2020-09-01T16:52:51Z","title":"Exploration in two-stage recommender systems"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2009.08956","kind":"arxiv","version":1},"verdict":{"created_at":null,"id":null,"model_set":{},"one_line_summary":"","pipeline_version":null,"pith_extraction_headline":"","strongest_claim":"","weakest_assumption":""}},"verdict_id":null}}],"author_attestations":[],"timestamp_anchors":[],"storage_attestations":[],"citation_signatures":[],"replication_records":[],"corrections":[],"mirror_hints":[],"record_created":{"event_id":"sha256:244d891cddd751b821aae0de923eb7c18e230b44973180fe2a6707624e286d00","target":"record","created_at":"2026-07-05T01:36:24Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"attestation_state":"computed","canonical_record":{"metadata":{"abstract_canon_sha256":"3a4406fdbed0498e8c4a1a31b9fb176f36bce975deb1bd80a7d4ecfbe165547f","cross_cats_sorted":["cs.LG","stat.ML"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IR","submitted_at":"2020-09-01T16:52:51Z","title_canon_sha256":"8ef1c60bc56ccf27e24ca885f399c26a8ad5b14f12ed0995c9bfa46e6acdf41c"},"schema_version":"1.0","source":{"id":"2009.08956","kind":"arxiv","version":1}},"canonical_sha256":"fec5d0515c4f5f38760d01de5bd383cd435240d3f1b07eb32f451189ae5c5f09","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"fec5d0515c4f5f38760d01de5bd383cd435240d3f1b07eb32f451189ae5c5f09","first_computed_at":"2026-07-05T01:36:24.068163Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T01:36:24.068163Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"quabE3/R2kvKIytsjDPYI654QGmSoEEBkx1NRqJwViAbjKC11f+T7GP+lfx7AKQ4i8Xr+xeRhgN9rSSlspNJDg==","signature_status":"signed_v1","signed_at":"2026-07-05T01:36:24.068556Z","signed_message":"canonical_sha256_bytes"},"source_id":"2009.08956","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:244d891cddd751b821aae0de923eb7c18e230b44973180fe2a6707624e286d00","sha256:9f8ca72b435838b1e85c3bec0d7c008a483485eac2df4b75f73dbb9168fd4b62"],"state_sha256":"669b1bf725424be5bc0d01bf2cb2a44789f13e34b8a25438552abb77f9041948"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"yCfGowo8xpR1Ikzsl+fc29wPKwzfnH6/eS/Zg14E6g3vJSUr3NeVqZO9UAq/UqrLvd7VFiZJQFgHEXC87agrAw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-08-24T00:30:02.201091Z","bundle_sha256":"84891ad8938c481cb31e24747fb058ed5ab4b95b2be163c607cfdfffbc52bf74"}}