{"paper":{"title":"StoryScope: Investigating idiosyncrasies in AI fiction","license":"http://creativecommons.org/publicdomain/zero/1.0/","headline":"Narrative features alone distinguish AI fiction from human writing at 93 percent accuracy.","cross_cats":[],"primary_cat":"cs.CL","authors_text":"Chau Minh Pham, Jenna Russell, John Wieting, Mohit Iyyer, Rishanth Rajendhran","submitted_at":"2026-04-03T15:56:38Z","abstract_excerpt":"As AI-generated fiction becomes increasingly prevalent, questions of authorship and originality are becoming central to how written work is evaluated. While most existing work in this space focuses on identifying surface-level signatures of AI writing, we ask instead whether AI-generated stories can be distinguished from human ones without relying on stylistic signals, focusing on discourse-level narrative choices such as character agency and chronological discontinuity. We propose StoryScope, a pipeline that automatically induces a fine-grained, interpretable feature space of discourse-level "},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"Narrative features alone achieve 93.2% macro-F1 for human vs. AI detection and 68.4% macro-F1 for six-way authorship attribution, retaining over 97% of the performance of models that include stylistic cues.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"That the automatically induced discourse-level features capture narrative choices independent of surface stylistic signals and that the parallel corpus of prompts sufficiently controls for content to isolate true narrative differences.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"StoryScope extracts narrative features showing AI stories favor tidy plots and over-explain themes while human stories show more moral ambiguity and temporal complexity, enabling strong detection and attribution.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"Narrative features alone distinguish AI fiction from human writing at 93 percent accuracy.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"f346c51796a483c39b70f7f30535455d78830204c2d6047f15ed03383dcbc734"},"source":{"id":"2604.03136","kind":"arxiv","version":5},"verdict":{"id":"f798570f-9403-473c-ae8d-f084c80a9cdb","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-13T20:21:18.491973Z","strongest_claim":"Narrative features alone achieve 93.2% macro-F1 for human vs. AI detection and 68.4% macro-F1 for six-way authorship attribution, retaining over 97% of the performance of models that include stylistic cues.","one_line_summary":"StoryScope extracts narrative features showing AI stories favor tidy plots and over-explain themes while human stories show more moral ambiguity and temporal complexity, enabling strong detection and attribution.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"That the automatically induced discourse-level features capture narrative choices independent of surface stylistic signals and that the parallel corpus of prompts sufficiently controls for content to isolate true narrative differences.","pith_extraction_headline":"Narrative features alone distinguish AI fiction from human writing at 93 percent accuracy."},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2604.03136/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":2,"snapshot_sha256":"4ea033bf1e6aaedf50057541176ee1954079f154b1e7f287cbced3cf7527e1ae"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}