Datasets:

hallucite-org
/

benchmark

case_file stringclasses 16 values	cite_idx int64 0 34	citation_text stringlengths 33 122	citation stringlengths 9 28	validity stringclasses 3 values	parallel_citation stringclasses 16 values	correct_case_name stringclasses 1 value	correct_citation stringclasses 2 values	src_same_case_name stringclasses 7 values	src_same_citation stringclasses 7 values	src_notes stringclasses 2 values
1__gpt-6-sol__791115	0	Bell Atlantic Corp. v. Twombly, 550 U.S. 544, 555, 570 (2007)	550 U.S. 544	strict	null	null	null	null	null	null
1__gpt-6-sol__791115	1	Ashcroft v. Iqbal, 556 U.S. 662, 678–79 (2009)	556 U.S. 662	strict	null	null	null	null	null	null
1__gpt-6-sol__791115	2	Swierkiewicz v. Sorema N.A., 534 U.S. 506, 510–12 (2002)	534 U.S. 506	strict	null	null	null	null	null	null
1__gpt-6-sol__791115	3	Khalik v. United Air Lines, 671 F.3d 1188, 1192–94 (10th Cir. 2012)	671 F.3d 1188	strict	null	null	null	null	null	null
1__gpt-6-sol__791115	4	C.R. England, Inc. v. Swift Transportation Co., 644 F.3d 1028, 1051 (10th Cir. 2011)	644 F.3d 1028	invalid	null	null	null	437 P.3d 343	E.E.O.C. v. C.R. England, Inc.	null
1__gpt-6-sol__791115	5	Den Hartog v. Wasatch Academy, 129 F.3d 1076, 1082–85 (10th Cir. 1997)	129 F.3d 1076	strict	null	null	null	null	null	null
1__gpt-6-sol__791115	6	Trujillo v. PacifiCorp, 524 F.3d 1149, 1154–56 (10th Cir. 2008)	524 F.3d 1149	strict	null	null	null	null	null	null
1__gpt-6-sol__791115	7	Metzler v. Federal Home Loan Bank of Topeka, 464 F.3d 1164, 1171–72 (10th Cir. 2006)	464 F.3d 1164	strict	null	null	null	null	null	null
1__gpt-6-sol__791115	8	Ames v. Ohio Department of Youth Services, 605 U.S. 303 (2025)	605 U.S. 303	strict	null	null	null	null	null	null
1__gpt-6-sol__791115	9	Burk v. K-Mart Corp., 770 P.2d 24, 28–29 (Okla. 1989)	770 P.2d 24	strict	null	null	null	null	null	null
1__gpt-6-sol__791115	10	Darrow v. Integris Health, Inc., 2008 OK 1	2008 OK 1	strict	176 P.3d 1204	null	null	null	null	null
1__gpt-6-sol__791115	11	Vasek v. Board of County Commissioners, 2008 OK 35	2008 OK 35	strict	186 P.3d 928	null	null	null	null	null
1__gemini-3.8-flash__794788	0	Bell Atl. Corp. v. Twombly, 550 U.S. 544, 570 (2007)	550 U.S. 544	strict	null	null	null	null	null	null
1__gemini-3.8-flash__794788	1	Ashcroft v. Iqbal, 556 U.S. 662, 678 (2009)	556 U.S. 662	strict	null	null	null	null	null	null
1__gemini-3.8-flash__794788	2	Whitney v. New Mexico, 113 F.3d 1170, 1173–74 (10th Cir. 1997)	113 F.3d 1170	strict	null	null	null	null	null	null
1__gemini-3.8-flash__794788	3	Radloff-Wilcox Funeral Home, Inc. v. Shannon, 963 F.3d 1002, 1007 (10th Cir. 2020)	963 F.3d 1002	invalid	null	null	null	null	null	null
1__gemini-3.8-flash__794788	4	Lindsey v. City of Woodward, 2011 OK CIV APP 109, ¶ 7	2011 OK CIV APP 109	invalid	268 P.3d 547	null	null	null	Tyson Foods, Inc., Own Risk No. 12220 v. Watson	null
1__gemini-3.8-flash__794788	5	Parker v. Brown, 317 U.S. 341 (1943)	317 U.S. 341	strict	null	null	null	null	null	null
1__gemini-3.8-flash__794788	6	Town of Hallie v. City of Eau Claire, 471 U.S. 34, 40 (1985)	471 U.S. 34	strict	null	null	null	null	null	null
1__gemini-3.8-flash__794788	7	City of Columbia v. Omni Outdoor Advert., Inc., 499 U.S. 365, 373 (1991)	499 U.S. 365	strict	null	null	null	null	null	null
1__gemini-3.8-flash__794788	8	United States v. Grinnell Corp., 384 U.S. 563, 570–71 (1966)	384 U.S. 563	strict	null	null	null	null	null	null
1__gemini-3.8-flash__794788	9	Lenox MacLaren Surgical Corp. v. Medtronic, Inc., 762 F.3d 1114, 1119 (10th Cir. 2014)	762 F.3d 1114	strict	null	null	null	null	null	null
1__gemini-3.8-flash__794788	10	Campfield v. State Farm Mut. Auto. Ins. Co., 532 F.3d 1111, 1118 (10th Cir. 2008)	532 F.3d 1111	strict	null	null	null	null	null	null
1__gemini-3.8-flash__794788	11	Verizon Communications Inc. v. Law Offices of Curtis V. Trinko, LLP, 540 U.S. 398, 410–11 (2004)	540 U.S. 398	strict	null	null	null	null	null	null
1__gemini-3.8-flash__794788	12	Aspen Highlands Skiing Corp. v. Aspen Skiing Co., 738 F.2d 1509, 1520 (10th Cir. 1984)	738 F.2d 1509	strict	null	null	null	null	null	null
1__gemini-3.8-flash__794788	13	Beeman v. Blue Cross & Blue Shield of Kan., Inc., 2001 OK 13, ¶ 10	2001 OK 13	invalid	27 P.3d 497	null	null	null	State ex rel. Oklahoma Bar Ass'n v. Simank	null
1__gemini-3.8-flash__794788	14	Gonzaga Univ. v. Doe, 536 U.S. 273, 283 (2002)	536 U.S. 273	strict	null	null	null	null	null	null
1__gemini-3.8-flash__794788	15	Blessing v. Freestone, 520 U.S. 329, 340 (1997)	520 U.S. 329	strict	null	null	null	null	null	null
1__gemini-3.8-flash__794788	16	Interface Grp., Inc. v. Mass. Port Auth., 816 F.2d 9, 15 (1st Cir. 1987)	816 F.2d 9	strict	null	null	null	null	null	null
1__gemini-3.8-flash__794788	17	Nw. Airlines, Inc. v. Cnty. of Kent, 955 F.2d 1054, 1058 (6th Cir. 1992)	955 F.2d 1054	strict	null	null	null	null	null	null
1__gemini-3.8-flash__794788	18	Four Corners Helicopters, Inc. v. Town of Farmington, 68 F.3d 483 (Table), 1995 WL 607641, at *2 (10th Cir. Oct. 17, 1995)	68 F.3d 483	invalid	1995 WL 607641	null	null	null	Jepsen v. Texaco, Inc.	multiple unpublished at this citation
1__gemini-3.8-flash__794788	19	Adair v. City of Muskogee, 823 F.3d 1297, 1312 (10th Cir. 2016)	823 F.3d 1297	strict	null	null	null	null	null	null
1__gemini-3.8-flash__794788	20	Collins v. City of Harker Heights, 503 U.S. 115, 119 (1992)	503 U.S. 115	strict	null	null	null	null	null	null
1__gemini-3.8-flash__794788	21	Sanders v. Indep. Sch. Dist. No. I-2, 459 F.2d 459, 461 (10th Cir. 1972)	459 F.2d 459	referential	null	null	459 F.2d 51	null	null	null
1__gemini-3.8-flash__794788	22	Village of Willowbrook v. Olech, 528 U.S. 562 (2000)	528 U.S. 562	strict	null	null	null	null	null	null
1__gemini-3.8-flash__794788	23	Kan. Penn Gaming, LLC v. Collins, 656 F.3d 1210, 1216 (10th Cir. 2011)	656 F.3d 1210	strict	null	null	null	null	null	null
1__gemini-3.8-flash__794788	24	Monell v. Department of Social Services, 436 U.S. 658, 694 (1978)	436 U.S. 658	strict	null	null	null	null	null	null
1__gemini-3.8-flash__794788	25	Schneider v. City of Grand Junction Police Dep't, 717 F.3d 760, 769–70 (10th Cir. 2013)	717 F.3d 760	strict	null	null	null	null	null	null
1__gemini-3.8-flash__794788	26	Digital Design Grp., Inc. v. Info. Builders, Inc., 2001 OK 21, ¶ 14	2001 OK 21	strict	24 P.3d 834	null	null	null	null	null
1__gemini-3.8-flash__794788	27	OKC Alley, LLC v. Edwards, 2015 OK CIV APP 72, ¶ 13	2015 OK CIV APP 72	invalid	358 P.3d 285	null	null	null	International Ass'n of Fire Fighters v. Public Employees Relations Bd.	null
1__gemini-3.8-flash__794788	28	Midwest Eng'g & Constr. Co. v. Elec. Indus., Inc., 1966 OK 184, ¶ 10	1966 OK 184	invalid	421 P.2d 212	null	null	null	Ray v. Oklahoma Turnpike Authority	null
1__gemini-3.8-flash__794788	29	Total Tel. Serv., LLC v. TPX Commc'ns, No. CIV-20-435-D, 2021 WL 4498651, at 5 (W.D. Okla. Sept. 30, 2021)	2021 WL 4498651	invalid	null	null	null	null	Johns v. Chemtech Services, Inc.	null
1__gemini-3.8-flash__794788	30	Dixon v. Bhuiyan, 2000 OK 56, ¶ 9	2000 OK 56	strict	10 P.3d 888	null	null	null	null	null
1__gemini-3.8-flash__794788	31	Strong v. State ex rel. Okla. Police Pension & Ret. Bd., 2005 OK 45, ¶ 12	2005 OK 45	strict	115 P.3d 889	null	null	null	null	null
1__gemini-3.8-flash__794788	32	City of Bixby v. State ex rel. Dep't of Transp., 1996 OK CIV APP 118, ¶ 9	1996 OK CIV APP 118	referential	934 P.2d 364	City of Bixby v. State ex rel. Dept. of Labor	null	null	null	null
1__gemini-3.8-flash__794788	33	City of Newport v. Fact Concerts, Inc., 453 U.S. 247, 271 (1981)	453 U.S. 247	strict	null	null	null	null	null	null
1__gemini-3.8-flash__794788	34	State ex rel. Okla. Corp. Comm'n v. McPherson, 2010 OK 31, ¶ 18	2010 OK 31	strict	232 P.3d 458	null	null	null	null	null
1__gpt-5__2827743	0	Ashcroft v. Iqbal, 556 U.S. 662, 678 (2009)	556 U.S. 662	strict	null	null	null	null	null	null
1__gpt-5__2827743	1	Bell Atl. Corp. v. Twombly, 550 U.S. 544, 570 (2007)	550 U.S. 544	strict	null	null	null	null	null	null
1__gpt-5__2827743	2	Great Lakes Dredge & Dock Co. LLC v. La. State, 624 F.3d 201, 210 (5th Cir. 2010)	624 F.3d 201	strict	null	null	null	null	null	null
1__gpt-5__2827743	3	In re Katrina Canal Breaches Litig., 495 F.3d 191, 205 (5th Cir. 2007)	495 F.3d 191	strict	null	null	null	null	null	null
1__gpt-5__2827743	4	Chhim v. Univ. of Tex. at Austin, 836 F.3d 467, 470 (5th Cir. 2016)	836 F.3d 467	strict	null	null	null	null	null	null
1__gpt-5__2827743	5	Raj v. La. State Univ., 714 F.3d 322, 331 (5th Cir. 2013)	714 F.3d 322	strict	null	null	null	null	null	null
1__gpt-5__2827743	6	Turner v. Kansas City S. Ry. Co., 675 F.3d 887, 892–93 (5th Cir. 2012)	675 F.3d 887	strict	null	null	null	null	null	null
1__gpt-5__2827743	7	Okoye v. Univ. of Tex. Houston Health Sci. Ctr., 245 F.3d 507, 514 (5th Cir. 2001)	245 F.3d 507	strict	null	null	null	null	null	null
1__gpt-5__2827743	8	Lee v. Kansas City S. Ry. Co., 574 F.3d 253, 260 (5th Cir. 2009)	574 F.3d 253	strict	null	null	null	null	null	null
1__gpt-5__2827743	9	Morris v. Town of Independence, 827 F.3d 396, 400 (5th Cir. 2016)	827 F.3d 396	strict	null	null	null	null	null	null
1__gemini-2.5-flash__787282	0	Bell Atlantic Corp. v. Twombly, 550 U.S. 544, 570 (2007)	550 U.S. 544	strict	null	null	null	null	null	null
1__gemini-2.5-flash__787282	1	Ashcroft v. Iqbal, 556 U.S. 662, 678 (2009)	556 U.S. 662	strict	null	null	null	null	null	null
1__gemini-2.5-flash__787282	2	Kansas v. United States, 852 F.3d 1294, 1298 (10th Cir. 2017)	852 F.3d 1294	invalid	null	null	null	124 F.4th 529 (8th Cir. 2024)	null	null
1__gemini-2.5-flash__787282	3	Casanova v. Ulibarri, 917 F.3d 1128, 1137 (10th Cir. 2019)	917 F.3d 1128	invalid	null	null	null	595 F.3d 1120 (10th Cir. 2010)	null	null
1__gemini-2.5-flash__787282	4	McDonnell Douglas Corp. v. Green, 411 U.S. 792, 802 (1973)	411 U.S. 792	strict	null	null	null	null	null	null
1__gemini-2.5-flash__787282	5	Khalik v. United Air Lines, 671 F.3d 1188, 1192 (10th Cir. 2012)	671 F.3d 1188	strict	null	null	null	null	null	null
1__gemini-2.5-flash__787282	6	E.E.O.C. v. PVNF, LLC, 487 F.3d 790, 800 (10th Cir. 2007)	487 F.3d 790	strict	null	null	null	null	null	null
1__gemini-2.5-flash__787282	7	Hernandez v. Valley View Hosp. Ass'n, 684 F.3d 950, 957 (10th Cir. 2012)	684 F.3d 950	strict	null	null	null	null	null	null
1__gemini-2.5-flash__787282	8	Harris v. Forklift Systems, Inc., 510 U.S. 17, 21-22 (1993)	510 U.S. 17	strict	null	null	null	null	null	null
1__gemini-2.5-flash__787282	9	Penry v. Fed. Home Loan Bank of Topeka, 155 F.3d 1257, 1261 (10th Cir. 1998)	155 F.3d 1257	strict	null	null	null	null	null	null
1__gemini-2.5-flash__787282	10	Oncale v. Sundowner Offshore Servs., Inc., 523 U.S. 75, 80 (1998)	523 U.S. 75	strict	null	null	null	null	null	null
1__gemini-2.5-flash__787282	11	Hicks v. Gates Rubber Co., 833 F.2d 1406, 1413 (10th Cir. 1987)	833 F.2d 1406	strict	null	null	null	null	null	null
1__gemini-2.5-flash__787282	12	Jones v. United Parcel Serv., Inc., 674 F.3d 1187, 1196 (10th Cir. 2012)	674 F.3d 1187	strict	null	null	null	null	null	null
1__gemini-2.5-flash__787282	13	O'Neal v. Ferguson Constr. Co., 237 F.3d 1248, 1253 (10th Cir. 2001)	237 F.3d 1248	strict	null	null	null	null	null	null
1__gemini-2.5-flash__787282	14	Argo v. Blue Cross and Blue Shield of Kansas, Inc., 452 F.3d 1193, 1202 (10th Cir. 2006)	452 F.3d 1193	strict	null	null	null	null	null	null
1__gemini-2.5-flash__787282	15	Petersen v. Utah Dep't of Corr., 301 F.3d 1182, 1188 (10th Cir. 2002)	301 F.3d 1182	strict	null	null	null	null	null	null
1__gemini-2.5-flash__787282	16	Den Hartog v. Wasatch Academy, 129 F.3d 1076, 1085 (10th Cir. 1997)	129 F.3d 1076	strict	null	null	null	null	null	null
1__gemini-2.5-flash__787282	17	Prost v. City of Olathe, 959 F. Supp. 2d 1295, 1313 (D. Kan. 2013)	959 F. Supp. 2d 1295	invalid	null	null	null	null	null	null
1__gemini-3-flash__1777712	0	Ashcroft v. Iqbal, 556 U.S. 662, 678 (2009)	556 U.S. 662	strict	null	null	null	null	null	null
1__gemini-3-flash__1777712	1	Bell Atl. Corp. v. Twombly, 550 U.S. 544, 570 (2007)	550 U.S. 544	strict	null	null	null	null	null	null
1__gemini-3-flash__1777712	2	Aetna Health Inc. v. Davila, 542 U.S. 200, 209 (2004)	542 U.S. 200	strict	null	null	null	null	null	null
1__gemini-3-flash__1777712	3	Hogan v. Kraft Foods, 969 F.2d 142, 144 (5th Cir. 1992)	969 F.2d 142	strict	null	null	null	null	null	null
1__gemini-3-flash__1777712	4	Ellis v. Liberty Life Assurance Co. of Boston, 394 F.3d 262, 276 (5th Cir. 2004)	394 F.3d 262	strict	null	null	null	null	null	null
1__gemini-3-flash__1777712	5	Heimeshoff v. Hartford Life & Accident Ins. Co., 571 U.S. 99, 105 (2013)	571 U.S. 99	strict	null	null	null	null	null	null
1__gemini-3-flash__1777712	6	Innova Hosp. San Antonio, L.P. v. Blue Cross & Blue Shield of Georgia, Inc., 892 F.3d 719, 728 (5th Cir. 2018)	892 F.3d 719	strict	null	null	null	null	null	null
1__gemini-3-flash__1777712	7	Mello v. Sara Lee Corp., 431 F.3d 440, 444-45 (5th Cir. 2005)	431 F.3d 440	strict	null	null	null	null	null	null
1__gemini-3-flash__1777712	8	Massachusetts Mut. Life Ins. Co. v. Russell, 473 U.S. 134, 148 (1985)	473 U.S. 134	strict	null	null	null	null	null	null
1__claude-sonnet-5__780127	0	Ashcroft v. Iqbal, 556 U.S. 662, 678 (2009)	556 U.S. 662	strict	null	null	null	null	null	null
1__claude-sonnet-5__780127	1	Bell Atlantic Corp. v. Twombly, 550 U.S. 544, 570 (2007)	550 U.S. 544	strict	null	null	null	null	null	null
1__claude-sonnet-5__780127	2	Red Hawk, L.L.C. v. Schneider, 493 F.3d 1174, 1177 (10th Cir. 2007)	493 F.3d 1174	strict	null	null	null	null	null	null
1__claude-sonnet-5__780127	3	Robbins v. Oklahoma, 519 F.3d 1242, 1250 (10th Cir. 2008)	519 F.3d 1242	strict	null	null	null	null	null	null
1__claude-sonnet-5__780127	4	Robinson v. Kansas, 295 F.3d 1183, 1189 (10th Cir. 2002)	295 F.3d 1183	strict	null	null	null	null	null	null
1__claude-sonnet-5__780127	5	EEOC v. C.R. England, Inc., 644 F.3d 1028, 1038–40 (10th Cir. 2011)	644 F.3d 1028	strict	null	null	null	null	null	null
1__claude-sonnet-5__780127	6	Harris v. Forklift Sys., Inc., 510 U.S. 17, 21 (1993)	510 U.S. 17	strict	null	null	null	null	null	null
1__claude-sonnet-5__780127	7	Faragher v. City of Boca Raton, 524 U.S. 775, 788 (1998)	524 U.S. 775	strict	null	null	null	null	null	null
1__claude-sonnet-5__780127	8	Morris v. City of Colo. Springs, 666 F.3d 654, 666 (10th Cir. 2012)	666 F.3d 654	strict	null	null	null	null	null	null
1__claude-sonnet-5__780127	9	Mason v. Avaya Commc'ns, Inc., 357 F.3d 1114, 1122–23 (10th Cir. 2004)	357 F.3d 1114	strict	null	null	null	null	null	null
1__claude-sonnet-5__780127	10	Hennagir v. Utah Dep't of Corr., 587 F.3d 1255, 1264–65 (10th Cir. 2009)	587 F.3d 1255	strict	null	null	null	null	null	null
1__claude-sonnet-5__780127	11	Cummings v. Premier Rehab Keller, P.L.L.C., 596 U.S. 212, 220–30 (2022)	596 U.S. 212	strict	null	null	null	null	null	null
1__claude-sonnet-5__780127	12	Pennhurst State Sch. & Hosp. v. Halderman, 465 U.S. 89, 98 (1984)	465 U.S. 89	strict	null	null	null	null	null	null
1__claude-sonnet-5__780127	13	Edelman v. Jordan, 415 U.S. 651, 663 (1974)	415 U.S. 651	strict	null	null	null	null	null	null
1__claude-sonnet-5__780127	14	Bd. of Trs. of the Univ. of Ala. v. Garrett, 531 U.S. 356, 360, 374 (2001)	531 U.S. 356	strict	null	null	null	null	null	null
1__claude-sonnet-5__780127	15	Sutton v. Utah State Sch. for the Deaf & Blind, 173 F.3d 1226, 1237 (10th Cir. 1999)	173 F.3d 1226	strict	null	null	null	null	null	null

End of preview. Expand in Data Studio

Citation-Checker Benchmark

A benchmark of whole legal briefs with hand-labelled citations, together with the reports that four citation checkers produced on those briefs: Westlaw, Lexis+, isthiscasereal.com and Hallucite. Every checker was given the same document and its report was aligned to the labels.

The inputs and labels are in data/; the checkers' raw output and our parsed results are in results/.

Components

Each component is a separate config. Components are scored and reported separately, never pooled.

config	split	documents	labelled citations	what it is
`charlotin-train`	`train`	40	567	Filings from cases in Damien Charlotin's AI Hallucination Cases database, mostly cases dated March-July 2025, plus a few early well-known cases and every S.D. Tex., W.D. Okla. and E.D.N.Y. case in the database at the time. Compiled in July 2025.
`charlotin-test`	`test`	9	158	A random sample of cases in the same database, taken in October 2026.
`ai-gen`	`test`	16	214	Motions to dismiss drafted by LLMs from real federal complaints.

Together that is 65 documents and 939 citations.

charlotin-train was used to improve Hallucite, so it is not a fair benchmark for comparing Hallucite with the other checkers. The split names reflect this. charlotin-test and ai-gen played no role in developing Hallucite.

The Charlotin components

Charlotin's database typically links only to a court order, not to the filing that contained the hallucinated citations. For each case we tried to find the original filing. When we could not obtain it (filings were sometimes stricken from the record), we either skipped the case or used the court order instead, so some documents here are orders rather than filings. The database stores metadata about the cases, not the documents; the text is public court record, included here as extracted.

`ai-gen`

Complaints filed in 2024 or 2025, with embedded text between 10,000 and 32,000 characters, were sampled evenly across S.D. Tex., W.D. Okla. and N.D. Okla. Each of eight models was given a complaint and a minimal prompt and asked for a motion to dismiss: GPT 4o, GPT 5, GPT 6-Sol, Claude 4 Sonnet, Claude 5 Sonnet, Gemini 2.5 Flash, Gemini 3 Flash and Gemini 3.8 Flash. The models were accessed through OpenRouter with default temperature, default reasoning levels and no tools (no internet access). No model was asked to fabricate citations. The briefs are model output, not real filings.

Files

data/<config>/<document>.txt        the document's text (also .docx: the same text, reflowed)
data/<config>/labels.csv            one row per citation occurrence (the dataset viewer shows this)
data/<config>/documents.csv         per-document metadata (briefs.csv for ai-gen)
results/<system>/<config>/          each system's raw output, exactly as produced
results/<system>/ledger.<config>.csv   our parsed result: one row per labelled citation

A document's id is its filename stem. Raw results and the label file's case_file column use the same stem, so everything joins back to its input.

The .docx files were uploaded to Westlaw and Lexis; they carry the same text as the .txt with lines reflowed into paragraphs and page-number lines dropped, because Lexis cannot read a citation that crosses a line break. isthiscasereal.com was given the same reflowed text (pasted, in pieces of at most 15 citations, since it accepts at most 20 per request).

Labels

For each document we extracted all full case citations (short-form citations and citations without a case name are excluded) and labelled each by hand, based on a search of Westlaw or Lexis. labels.csv has one row per citation occurrence.

column	meaning
`case_file`	the document's filename stem
`cite_idx`	0-based position of the citation in the document, in order of appearance
`citation_text`	the citation as written
`citation`	the cite alone, `volume reporter page`, normalized (e.g. `556 U.S. 662`)
`validity`	`strict`, `referential` or `invalid`
`parallel_citation`	a second cite to the same case, where the brief gave one
`correct_case_name`, `correct_citation`	for `referential` rows, the correction
`src_same_case_name`, `src_same_citation`	for an `invalid` citation that resolves to a real case with a different name, that case's name and citation
`src_notes`	provenance notes carried over from the source

validity:

strict: the citation is valid, allowing for reasonable variations in the case name.
referential: a reader can recover the intended authority despite an understandable typo in one party name or one component of the reporter citation, with no other errors.
invalid: the authority does not exist, or the reader cannot recover it from what is written. An invalid citation whose reporter cite points to a real case with an entirely different name is a collision (src_same_citation is filled in); otherwise it is nonexistent.

Citations are judged as the author wrote them: OCR or extraction noise in the text is not the author's error. Systems are scored under two standards: flagging only invalid, and flagging invalid plus referential.

Non-case authorities such as statutes and rules are not labelled.

Systems and results

system	product	input	run dates (2026)
`westlaw`	Westlaw Advantage, Litigation Document Analyzer ("Check your work")	the `.docx`	Oct 1-9 (`charlotin-train`), Oct 3-4 (`charlotin-test`), Oct 6-7 (`ai-gen`)
`lexis`	Lexis+ Brief Analysis	the `.docx`	same dates as Westlaw
`isthiscasereal`	isthiscasereal.com	the reflowed text, in pieces	Oct 8-14 (`charlotin-train`), Oct 8 (others)
`hallucite`	Hallucite	the `.txt`	Oct 14 (`charlotin-train`), Oct 4 (`charlotin-test`), Oct 7 (`ai-gen`)

These products change without notice, so the dates matter. Raw output is stored as the system produced it: Westlaw's full report as .rtf (Word download), Lexis's report page as .mhtml (Chrome "Single File"), isthiscasereal.com's report pages as .html. Hallucite has no raw folder here, only a ledger.

Ledgers

results/<system>/ledger.<config>.csv is our parse of the raw output, joined to the labels. It can be regenerated from the raw files and the labels. One row per labelled citation.

column	meaning
`system`, `component`, `case_file`, `cite_idx`, `citation`, `citation_text`	which citation
`finding`	`citation_issue` (the system explicitly warned), `listed` (returned, nothing raised) or `absent` (the output never mentions it)
`flagged`	1 if `finding` is `citation_issue`
`found`	1 if the system mentioned the citation at all
`validity`	the label, copied from `labels.csv`
`vendor_case_name`, `vendor_citation`	what the system printed for this citation
`joined_on`	how the system's entry was matched to the label: `citation` (exact), `parallel_citation`, `case_at_citation`, or `pincite`
`vendor_section`, `vendor_resolution`, `vendor_reason`, `treatment_flag`	system-specific fields

How findings are read:

A citation is invalid if the system flags it as problematic, and valid otherwise. A citation the system's output never mentions is absent and is counted as wrong whatever the label: silence is not the same as checking a citation and finding nothing.
No case-name matching is involved. If a system lists a different case under the citation and says nothing, that is its judgment (listed); vendor_case_name beside citation_text lets you see the substitution.
Treatment flags (KeyCite, Shepard's) are not read as validity signals.
Hallucite's invalid, uncovered and unpublished statuses are warnings; exists and incomplete are listed. uncovered means the reporter is outside Hallucite's data, so it could not confirm the citation; scoring that as a flag matches how the other systems treat citations they hold no data for.

Limitations

Labels are hand-made and may contain errors.
charlotin-train was used to improve Hallucite (above).
Westlaw, Lexis and isthiscasereal.com were used through their web interfaces and Hallucite was run locally. Vendor products change, so these are results for those dates, not for the products in general.
Some Charlotin documents are court orders rather than the original filings.
ai-gen briefs contain fabricated citations produced by language models. They are not real filings.

License and provenance

The labels, ledgers and this README are released under CC-BY-4.0. The Charlotin documents are public court records. The ai-gen documents are text generated by language models from public complaints. The files under results/westlaw, results/lexis and results/isthiscasereal are the output of those services and remain subject to their owners' terms.

To request removal of anything here, contact bl759@cornell.edu.

Downloads last month: 38

Collection including hallucite-org/benchmark

Hallucite

Collection

Datasets, benchmark, and results from the paper "Hallucite: Automated Detection of Hallucinated Case Citations in Real-World Court Filings" • 3 items • Updated 6 days ago