{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2026:SZJEROZ2QHZOVZFDWLPNDWJWDV","short_pith_number":"pith:SZJEROZ2","canonical_record":{"source":{"id":"2605.18206","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"stat.ME","submitted_at":"2026-05-18T10:45:31Z","cross_cats_sorted":[],"title_canon_sha256":"4398bbd5dd22d1a058baaf6bb4e7e428dd9caee076746ab1bec54f0b7bd40ec2","abstract_canon_sha256":"0c01765cca27476fd83ccba498fe9e3fcf9ea325134383aee9fe27cd8879c0e2"},"schema_version":"1.0"},"canonical_sha256":"965248bb3a81f2eae4a3b2ded1d9361d57fe8f37b5f6b1383da8d24082b9fa61","source":{"kind":"arxiv","id":"2605.18206","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2605.18206","created_at":"2026-05-20T00:05:50Z"},{"alias_kind":"arxiv_version","alias_value":"2605.18206v1","created_at":"2026-05-20T00:05:50Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2605.18206","created_at":"2026-05-20T00:05:50Z"},{"alias_kind":"pith_short_12","alias_value":"SZJEROZ2QHZO","created_at":"2026-05-20T00:05:50Z"},{"alias_kind":"pith_short_16","alias_value":"SZJEROZ2QHZOVZFD","created_at":"2026-05-20T00:05:50Z"},{"alias_kind":"pith_short_8","alias_value":"SZJEROZ2","created_at":"2026-05-20T00:05:50Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2026:SZJEROZ2QHZOVZFDWLPNDWJWDV","target":"record","payload":{"canonical_record":{"source":{"id":"2605.18206","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"stat.ME","submitted_at":"2026-05-18T10:45:31Z","cross_cats_sorted":[],"title_canon_sha256":"4398bbd5dd22d1a058baaf6bb4e7e428dd9caee076746ab1bec54f0b7bd40ec2","abstract_canon_sha256":"0c01765cca27476fd83ccba498fe9e3fcf9ea325134383aee9fe27cd8879c0e2"},"schema_version":"1.0"},"canonical_sha256":"965248bb3a81f2eae4a3b2ded1d9361d57fe8f37b5f6b1383da8d24082b9fa61","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-20T00:05:50.542398Z","signature_b64":"CW1EAan2xQDTLBdWhM3CFzEZ09Lv4gfoy8QVIW22FQsfNyouIWSt+PFzz8fOomIsGL58nyhxdTW4Q5W/lBwoCg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"965248bb3a81f2eae4a3b2ded1d9361d57fe8f37b5f6b1383da8d24082b9fa61","last_reissued_at":"2026-05-20T00:05:50.541826Z","signature_status":"signed_v1","first_computed_at":"2026-05-20T00:05:50.541826Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2605.18206","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":"2026-05-20T00:05:50Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"8bCVGF+KZwMXDmiU8r3EJUPYkyh5NTIDhAwrLmZqTBe2TM2ZvNBzJyGS6fA52CGSL0ZOq64XYkOEfElg0ARqAQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-25T17:58:49.883533Z"},"content_sha256":"23a59ea9ec6a05a860169128b5c5e2e8104b09149c40b44c5ee829e03dd70000","schema_version":"1.0","event_id":"sha256:23a59ea9ec6a05a860169128b5c5e2e8104b09149c40b44c5ee829e03dd70000"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2026:SZJEROZ2QHZOVZFDWLPNDWJWDV","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"A tool to determine the degrees of freedom in tree-structured varying coefficient models","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"stat.ME","authors_text":"Moritz Berger, Nikolai Spuck","submitted_at":"2026-05-18T10:45:31Z","abstract_excerpt":"The tree-structured varying coefficient (TSVC) model is a flexible approach for generalized regression, where the linear effects of the covariates are allowed to vary with the values of effect modifiers. Relevant effect modifiers and interactions are identified using recursive partitioning. In TSVC models, analogously to other semi- and nonparametric regression approaches, one needs to account for the cost of data-driven model building when deriving the model degrees of freedom (DoF). To address this issue, we develop an easy-to-apply formula to approximate the DoF of a TSVC model. This formul"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2605.18206","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/2605.18206/integrity.json","findings":[],"available":true,"detectors_run":[{"name":"claim_evidence","ran_at":"2026-05-19T23:41:58.982812Z","status":"completed","version":"1.0.0","findings_count":0},{"name":"ai_meta_artifact","ran_at":"2026-05-19T23:33:35.315806Z","status":"skipped","version":"1.0.0","findings_count":0}],"snapshot_sha256":"5ca820e197f3a9a67996d0330400a9364984a011f0b63f23201825c6ff094f64"},"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":"2026-05-20T00:05:50Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"lryDZB2oAV1qnBKkNgEzfyJUfWY+ZcbpJfUIwn9DIRBN0FBgPHgz6sQpb8HVqe9QhyjaOnDGRuEOZLleMRqnBg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-25T17:58:49.884131Z"},"content_sha256":"6aa8c3b1264eaed7715c2e14cb20213741e27f977abd38467b74851f7e143132","schema_version":"1.0","event_id":"sha256:6aa8c3b1264eaed7715c2e14cb20213741e27f977abd38467b74851f7e143132"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/SZJEROZ2QHZOVZFDWLPNDWJWDV/bundle.json","state_url":"https://pith.science/pith/SZJEROZ2QHZOVZFDWLPNDWJWDV/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/SZJEROZ2QHZOVZFDWLPNDWJWDV/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":"2026-05-25T17:58:49Z","links":{"resolver":"https://pith.science/pith/SZJEROZ2QHZOVZFDWLPNDWJWDV","bundle":"https://pith.science/pith/SZJEROZ2QHZOVZFDWLPNDWJWDV/bundle.json","state":"https://pith.science/pith/SZJEROZ2QHZOVZFDWLPNDWJWDV/state.json","well_known_bundle":"https://pith.science/.well-known/pith/SZJEROZ2QHZOVZFDWLPNDWJWDV/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2026:SZJEROZ2QHZOVZFDWLPNDWJWDV","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":"0c01765cca27476fd83ccba498fe9e3fcf9ea325134383aee9fe27cd8879c0e2","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"stat.ME","submitted_at":"2026-05-18T10:45:31Z","title_canon_sha256":"4398bbd5dd22d1a058baaf6bb4e7e428dd9caee076746ab1bec54f0b7bd40ec2"},"schema_version":"1.0","source":{"id":"2605.18206","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2605.18206","created_at":"2026-05-20T00:05:50Z"},{"alias_kind":"arxiv_version","alias_value":"2605.18206v1","created_at":"2026-05-20T00:05:50Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2605.18206","created_at":"2026-05-20T00:05:50Z"},{"alias_kind":"pith_short_12","alias_value":"SZJEROZ2QHZO","created_at":"2026-05-20T00:05:50Z"},{"alias_kind":"pith_short_16","alias_value":"SZJEROZ2QHZOVZFD","created_at":"2026-05-20T00:05:50Z"},{"alias_kind":"pith_short_8","alias_value":"SZJEROZ2","created_at":"2026-05-20T00:05:50Z"}],"graph_snapshots":[{"event_id":"sha256:6aa8c3b1264eaed7715c2e14cb20213741e27f977abd38467b74851f7e143132","target":"graph","created_at":"2026-05-20T00:05:50Z","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":[{"findings_count":0,"name":"claim_evidence","ran_at":"2026-05-19T23:41:58.982812Z","status":"completed","version":"1.0.0"},{"findings_count":0,"name":"ai_meta_artifact","ran_at":"2026-05-19T23:33:35.315806Z","status":"skipped","version":"1.0.0"}],"endpoint":"/pith/2605.18206/integrity.json","findings":[],"snapshot_sha256":"5ca820e197f3a9a67996d0330400a9364984a011f0b63f23201825c6ff094f64","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"The tree-structured varying coefficient (TSVC) model is a flexible approach for generalized regression, where the linear effects of the covariates are allowed to vary with the values of effect modifiers. Relevant effect modifiers and interactions are identified using recursive partitioning. In TSVC models, analogously to other semi- and nonparametric regression approaches, one needs to account for the cost of data-driven model building when deriving the model degrees of freedom (DoF). To address this issue, we develop an easy-to-apply formula to approximate the DoF of a TSVC model. This formul","authors_text":"Moritz Berger, Nikolai Spuck","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"stat.ME","submitted_at":"2026-05-18T10:45:31Z","title":"A tool to determine the degrees of freedom in tree-structured varying coefficient models"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2605.18206","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":"sha256:23a59ea9ec6a05a860169128b5c5e2e8104b09149c40b44c5ee829e03dd70000","target":"record","created_at":"2026-05-20T00:05:50Z","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":"0c01765cca27476fd83ccba498fe9e3fcf9ea325134383aee9fe27cd8879c0e2","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"stat.ME","submitted_at":"2026-05-18T10:45:31Z","title_canon_sha256":"4398bbd5dd22d1a058baaf6bb4e7e428dd9caee076746ab1bec54f0b7bd40ec2"},"schema_version":"1.0","source":{"id":"2605.18206","kind":"arxiv","version":1}},"canonical_sha256":"965248bb3a81f2eae4a3b2ded1d9361d57fe8f37b5f6b1383da8d24082b9fa61","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"965248bb3a81f2eae4a3b2ded1d9361d57fe8f37b5f6b1383da8d24082b9fa61","first_computed_at":"2026-05-20T00:05:50.541826Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-20T00:05:50.541826Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"CW1EAan2xQDTLBdWhM3CFzEZ09Lv4gfoy8QVIW22FQsfNyouIWSt+PFzz8fOomIsGL58nyhxdTW4Q5W/lBwoCg==","signature_status":"signed_v1","signed_at":"2026-05-20T00:05:50.542398Z","signed_message":"canonical_sha256_bytes"},"source_id":"2605.18206","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:23a59ea9ec6a05a860169128b5c5e2e8104b09149c40b44c5ee829e03dd70000","sha256:6aa8c3b1264eaed7715c2e14cb20213741e27f977abd38467b74851f7e143132"],"state_sha256":"a2ec80d35474289478344543eaf890b0c009cfa2c4d3ca3be19e60d38876767f"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"SNrb1rBIc89BuVcKXybnNoeyHbD+OBeap6KDUXszwhxiId1oJ0zBt6zULqzy9LNUEqPu0WucowdxhrlnTBqmCg==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-25T17:58:49.887707Z","bundle_sha256":"6c1e16604817aac38e4d35fef56aca00428870342bff4f4a0be30198a847420f"}}