{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2022:OJQ5ZLOLHIVYNSBRHHWSFTYRQX","short_pith_number":"pith:OJQ5ZLOL","canonical_record":{"source":{"id":"2205.15931","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.NE","submitted_at":"2022-05-31T16:21:14Z","cross_cats_sorted":[],"title_canon_sha256":"d96b08a027a08953cb259a4245e4d2cc6d8b33d32f3bbef4a49bea30484a71df","abstract_canon_sha256":"37ce68769a4c546c514b57957a43b409501e21e938779e40da4a5459e10724db"},"schema_version":"1.0"},"canonical_sha256":"7261dcadcb3a2b86c83139ed22cf1185f37e8e016d7fb1f7a7f82f828b8d95ab","source":{"kind":"arxiv","id":"2205.15931","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2205.15931","created_at":"2026-07-05T04:28:03Z"},{"alias_kind":"arxiv_version","alias_value":"2205.15931v1","created_at":"2026-07-05T04:28:03Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2205.15931","created_at":"2026-07-05T04:28:03Z"},{"alias_kind":"pith_short_12","alias_value":"OJQ5ZLOLHIVY","created_at":"2026-07-05T04:28:03Z"},{"alias_kind":"pith_short_16","alias_value":"OJQ5ZLOLHIVYNSBR","created_at":"2026-07-05T04:28:03Z"},{"alias_kind":"pith_short_8","alias_value":"OJQ5ZLOL","created_at":"2026-07-05T04:28:03Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2022:OJQ5ZLOLHIVYNSBRHHWSFTYRQX","target":"record","payload":{"canonical_record":{"source":{"id":"2205.15931","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.NE","submitted_at":"2022-05-31T16:21:14Z","cross_cats_sorted":[],"title_canon_sha256":"d96b08a027a08953cb259a4245e4d2cc6d8b33d32f3bbef4a49bea30484a71df","abstract_canon_sha256":"37ce68769a4c546c514b57957a43b409501e21e938779e40da4a5459e10724db"},"schema_version":"1.0"},"canonical_sha256":"7261dcadcb3a2b86c83139ed22cf1185f37e8e016d7fb1f7a7f82f828b8d95ab","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T04:28:03.911008Z","signature_b64":"UGbprlmz5gKE3lI0SHDhFOQFk6G/Cl2aNdmn6Q451KNkV50ovPKZ3h34HQb39T07pwL6AOFQSl6agJSOvkHrDA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"7261dcadcb3a2b86c83139ed22cf1185f37e8e016d7fb1f7a7f82f828b8d95ab","last_reissued_at":"2026-07-05T04:28:03.910619Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T04:28:03.910619Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2205.15931","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":"2026-07-05T04:28:03Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"B5DtOui9SwST35pNLgIikJyhScE/iBdKAsQba81yQ0wrpiaTls4mJP1INlQ4c3iJBTqr9H/12ylYZgxYnx2GBw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-18T11:27:01.144682Z"},"content_sha256":"b807a30077c14b3483ed4492d653dc4be099cb6c443677c41f6e6e4933e1d69e","schema_version":"1.0","event_id":"sha256:b807a30077c14b3483ed4492d653dc4be099cb6c443677c41f6e6e4933e1d69e"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2022:OJQ5ZLOLHIVYNSBRHHWSFTYRQX","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"The Environmental Discontinuity Hypothesis for Down-Sampled Lexicase Selection","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"cs.NE","authors_text":"Lee Spector, Ryan Boldi, Thomas Helmuth","submitted_at":"2022-05-31T16:21:14Z","abstract_excerpt":"Down-sampling training data has long been shown to improve the generalization performance of a wide range of machine learning systems. Recently, down-sampling has proved effective in genetic programming (GP) runs that utilize the lexicase parent selection technique. Although this down-sampling procedure has been shown to significantly improve performance across a variety of problems, it does not seem to do so due to encouraging adaptability through environmental change. We hypothesize that the random sampling that is performed every generation causes discontinuities that result in the populati"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2205.15931","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/2205.15931/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":"2026-07-05T04:28:03Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"Rfiwaad12QP2tssz5nXhHGUEGPPc5Cb4ATR81DLMjfsNsmD2mC00eB5BHlcahIz5j6LBjQbAbuM6ClxEnZMxCQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-18T11:27:01.145249Z"},"content_sha256":"52ccc9ce67f5863cc3f140b97598f52c2c50a3685685abbb247da0d4d364ba1e","schema_version":"1.0","event_id":"sha256:52ccc9ce67f5863cc3f140b97598f52c2c50a3685685abbb247da0d4d364ba1e"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/OJQ5ZLOLHIVYNSBRHHWSFTYRQX/bundle.json","state_url":"https://pith.science/pith/OJQ5ZLOLHIVYNSBRHHWSFTYRQX/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/OJQ5ZLOLHIVYNSBRHHWSFTYRQX/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":"2026-08-18T11:27:01Z","links":{"resolver":"https://pith.science/pith/OJQ5ZLOLHIVYNSBRHHWSFTYRQX","bundle":"https://pith.science/pith/OJQ5ZLOLHIVYNSBRHHWSFTYRQX/bundle.json","state":"https://pith.science/pith/OJQ5ZLOLHIVYNSBRHHWSFTYRQX/state.json","well_known_bundle":"https://pith.science/.well-known/pith/OJQ5ZLOLHIVYNSBRHHWSFTYRQX/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2022:OJQ5ZLOLHIVYNSBRHHWSFTYRQX","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":"37ce68769a4c546c514b57957a43b409501e21e938779e40da4a5459e10724db","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.NE","submitted_at":"2022-05-31T16:21:14Z","title_canon_sha256":"d96b08a027a08953cb259a4245e4d2cc6d8b33d32f3bbef4a49bea30484a71df"},"schema_version":"1.0","source":{"id":"2205.15931","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2205.15931","created_at":"2026-07-05T04:28:03Z"},{"alias_kind":"arxiv_version","alias_value":"2205.15931v1","created_at":"2026-07-05T04:28:03Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2205.15931","created_at":"2026-07-05T04:28:03Z"},{"alias_kind":"pith_short_12","alias_value":"OJQ5ZLOLHIVY","created_at":"2026-07-05T04:28:03Z"},{"alias_kind":"pith_short_16","alias_value":"OJQ5ZLOLHIVYNSBR","created_at":"2026-07-05T04:28:03Z"},{"alias_kind":"pith_short_8","alias_value":"OJQ5ZLOL","created_at":"2026-07-05T04:28:03Z"}],"graph_snapshots":[{"event_id":"sha256:52ccc9ce67f5863cc3f140b97598f52c2c50a3685685abbb247da0d4d364ba1e","target":"graph","created_at":"2026-07-05T04:28:03Z","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/2205.15931/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"Down-sampling training data has long been shown to improve the generalization performance of a wide range of machine learning systems. Recently, down-sampling has proved effective in genetic programming (GP) runs that utilize the lexicase parent selection technique. Although this down-sampling procedure has been shown to significantly improve performance across a variety of problems, it does not seem to do so due to encouraging adaptability through environmental change. We hypothesize that the random sampling that is performed every generation causes discontinuities that result in the populati","authors_text":"Lee Spector, Ryan Boldi, Thomas Helmuth","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.NE","submitted_at":"2022-05-31T16:21:14Z","title":"The Environmental Discontinuity Hypothesis for Down-Sampled Lexicase Selection"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2205.15931","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:b807a30077c14b3483ed4492d653dc4be099cb6c443677c41f6e6e4933e1d69e","target":"record","created_at":"2026-07-05T04:28:03Z","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":"37ce68769a4c546c514b57957a43b409501e21e938779e40da4a5459e10724db","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.NE","submitted_at":"2022-05-31T16:21:14Z","title_canon_sha256":"d96b08a027a08953cb259a4245e4d2cc6d8b33d32f3bbef4a49bea30484a71df"},"schema_version":"1.0","source":{"id":"2205.15931","kind":"arxiv","version":1}},"canonical_sha256":"7261dcadcb3a2b86c83139ed22cf1185f37e8e016d7fb1f7a7f82f828b8d95ab","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"7261dcadcb3a2b86c83139ed22cf1185f37e8e016d7fb1f7a7f82f828b8d95ab","first_computed_at":"2026-07-05T04:28:03.910619Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T04:28:03.910619Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"UGbprlmz5gKE3lI0SHDhFOQFk6G/Cl2aNdmn6Q451KNkV50ovPKZ3h34HQb39T07pwL6AOFQSl6agJSOvkHrDA==","signature_status":"signed_v1","signed_at":"2026-07-05T04:28:03.911008Z","signed_message":"canonical_sha256_bytes"},"source_id":"2205.15931","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:b807a30077c14b3483ed4492d653dc4be099cb6c443677c41f6e6e4933e1d69e","sha256:52ccc9ce67f5863cc3f140b97598f52c2c50a3685685abbb247da0d4d364ba1e"],"state_sha256":"cebee82ae4aaa277568dbed0effc988c2f889bd9e5718fa481aac857c8b559d8"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"or5uXzWmCU02+URCQ+ilD//HiHdsLlkllrdvyejtXSQmIqyV6CmqpjXr7y8GYRw0KNURP6voGUlM+iTVpS05CA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-08-18T11:27:01.149066Z","bundle_sha256":"fedaf500236710d6a3daf686406bd472816adafb11cb941e29486db27cd84aab"}}