Don't Pick a Winner: Knowledge Conflicts Need a Prior, Not a Rule
Organizations: Posts and Telecommunications Institute of Technology, Hanoi, Vietnam
Abstract
A retrieval-augmented language model answers from two sources, the retrieved context and its own knowledge, and the two disagree whenever the context is incomplete or wrong. Existing methods settle the disagreement with a rule fixed at design time: follow the context, amplify it in proportion to how far it moves the model, or trust the model's memory. Each rule is confidently wrong in some deployment. In a decision-theoretic model of two sources, the score of any fixed rule is linear in the share of reliable contexts while the best attainable score is convex, so every fixed rule is beaten wherever it is not exactly optimal; and a symmetric divergence between the two sources, the signal adaptive decoding uses, carries no information about which one is right. Resolving a conflict therefore needs two inputs that no existing method keeps: evidence about each source separately, and a prior on how often the context is right. We test these claims on GRACE, a benchmark that intervenes on the knowledge-graph context of a fixed question, so that what the model knows, what the context says and what is true are measured separately. There, every baseline from four families is strong on right contexts or on wrong ones, never on both. We then build the two inputs: the model states its knowledge as notes, a small policy voices each note with a calibrated confidence, a reader answers in two voices, and a selector commits or abstains under a prior applied as an exact prior shift. With set to the true share of right contexts, the system is above the best baseline at every mixture of GRACE contexts, by up to 26 points. Its overall score is 45.3 and 35.0 (Qwen3.5-35B-A3B, Llama-3.1-8B), against 29.4 and 27.5 for the best baseline. On preregistered ClashEval it beats same-backbone CK-PLUG and TCR by 12 and 26 points. Where the model lacks the knowledge, the gains vanish, as the theory predicts.
Figures & tables
| Qwen3.5-35B-A3B | Llama-3.1-8B | |||
| Method | C W | C W | ||
| Ours | 45.3 | 35.0 | ||
| USC ( Chen et al., 2024b ) | 29.4 | [12.6, 19.1] | 26.5 | [4.8, 12.3] |
| plain reader | 22.6 | [19.8, 25.7] | 27.5 | [4.4, 10.6] |
| InstructRAG-ICL ( Wei et al., 2025 ) | 23.7 | [18.4, 24.8] | 20.1 | [11.6, 18.2] |
| Astute RAG ( Wang et al., 2025a ) | 21.7 | [19.8, 28.4] | 10.1 | [20.4, 29.5] |
Appendix figures & tables26 assets
Supplementary material from the paper’s appendix.
Appendix
| Definition | Measured by | |
|---|---|---|
| Acc1 (knows) | correct without any context | closed-book arm |
| Acc2 (reads) | answers what the context says, right or wrong | context-only arm, scored against the context's answer |
| Acc3 (is right) | answers the real-world answer | every method; the final objective |
| Split | Size | Use |
|---|---|---|
| Pool | 1,000 LC-QuAD-train questions × 4 states | training the note policy and the selector |
| Dev | 3 disjoint slices of 225 questions × 4 states = 2,700 records | development and all GRACE tables |
| GRACE-QT | 1,000 LC-QuAD-train questions of types absent from the pool (rank, qualified statement, boolean, string); 500 train / 500 dev; real Wikidata 1-hop context, no perturbation | question-type generalisation |
| Method | Uses model knowledge explicitly | Knowledge tied to individual context facts | Calibrated confidence | Both sources visible in the answer | Abstains | Interpretable control |
| FaithfulRAG, TruthfulRAG | partly (to find conflicts) | yes | no | no | no | no |
| Self-Route | only when context is silent | no | no | no | no | no |
| CK-PLUG, CAD, AdaCAD | implicitly (logits) | no | no | no | no | α (fixed, entropy- or divergence-based) |
| TCR, Knowledgeable-R1 | implicitly (trained) | no | no | no | no | no |
| InstructRAG, USC | implicitly | no | no | no | no | no |
| GenRead, Astute RAG | yes | no | self-reported | no | no | no |
| Baseline | Venue | Source used |
|---|---|---|
| FaithfulRAG | ACL 2025 | official code |
| TruthfulRAG | AAAI 2026 | official code |
| InstructRAG-ICL | ICLR 2025 | official code |
| GenRead | ICLR 2023 | official code |
| TCR | AAAI 2026 | official code, retrained with the authors' recipe (three fixes were needed to run it) |
| CK-PLUG | ICLR 2026 | official code, adaptive α (one line changed: a hard-coded GPU index) |
| Baseline | Code | What is unchanged | What had to be adapted |
|---|---|---|---|
| FaithfulRAG | official, commit 9181b11 | the authors' pipeline ( get_self_facts , get_topk_chunks , get_predictions , normal CoT), no line changed | the OpenAI-compatible backend points at our server |
| InstructRAG-ICL | official, commit 8147bbc | the authors' prompt builder and template; rationales generated on 200 GRACE-pool records; two random in-context examples as in the paper | chat tokens of the template changed to the backbone's |
| GenRead | official, commit 49828ba | the original prompts and add_prompt ; step 1 at most 300 tokens, step 2 at most 10, greedy | called through the chat template instead of the completion API. GenRead does not read the retrieved context |
| TruthfulRAG | official | the steps of TruthfulRAG.run() ; MiniLM on CPU as in the README | backend points at our server |
| CK-PLUG | official | eval_rag.py , mode ck , adaptive α, the "Q: … A:" prompt | one line: a hard-coded GPU index; the first output line is taken as the answer |
| CAD, AdaCAD | official arithmetic, commits 1281d7f (CAD) and 57508c3 (AdaCAD) | get_jsd and filter_logits_top_p taken verbatim from the AdaCAD file; per-step combination as in the code (CAD: weights 2 and −1, the authors' NQ-Swap setting; AdaCAD: α = JSD of the two distributions); greedy, 32 new tokens, the AdaCAD question-answering prompts, first output line as the answer (as in eval_qa.py ) | the official code holds one model copy per input in two processes on two GPUs and adds logits through torch.distributed ; we compute both passes in one process with one copy (the arithmetic is the same) |
| correct | abstain | wrong | |
| plain reader | 12.0 | 68.2 | 19.9 |
| CAD (fixed ) | 11.2 | 40.8 | 47.9 |
| AdaCAD ( = divergence) | 12.7 | 17.6 | 69.7 |
| ours ( Section 6 ) | 32.2 | 51.3 | 16.5 |
| Stance | Meaning |
|---|---|
| confirm | context fact Fi matches what the model knows |
| contradict | context fact Fi is wrong according to the model; the object is the value the model believes |
| add | additional knowledge about a related entity |
| bridge | knowledge that connects the question to the answer |
| 0.1 | 0.25 | 0.5 | 0.75 | 0.9 | 0.99 | |
| Qwen: best baseline | GenRead | Astute RAG | Astute RAG | USC | USC | USC |
| ours best | ||||||
| [19.3, 32.1] | [20.2, 31.5] | [16.3, 26.4] | [7.7, 15.1] | [ , 7.3] | [ , 5.5] | |
| Llama: best baseline | Astute RAG | plain reader | plain reader | USC | AdaCAD | AdaCAD |
| ours best | ||||||
| [4.9, 16.9] | [7.2, 16.2] | [0.4, 8.4] | [ , 8.8] | [ , 6.1] | [ , 4.9] |
| Qwen3.5-35B-A3B | Llama-3.1-8B | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| π | All | clean | broken | wrong | comp. | All | clean | broken | wrong | comp. |
| 0.1 | 44.8 (56.9 / 12.0) | 61.2 | 43.0 | 20.4 | 54.7 | 33.3 (45.4 / 12.0) | 53.5 | 34.7 | −0.6 | 45.8 |
| 0.25 | 45.3 (58.4 / 13.1) | 64.3 | 44.1 | 17.9 | 55.0 | 35.0 (48.5 / 13.6) | 57.5 | 37.6 | −4.1 | 48.9 |
| 0.5 | 43.4 (59.7 / 16.3) | 70.2 | 44.9 | 4.0 | 54.4 | 34.1 (54.0 / 19.8) | 64.9 | 39.1 | −19.6 | 52.1 |
| 0.75 | 38.8 (59.2 / 20.4) | 72.6 | 45.6 | −14.5 | 51.6 | 30.0 (55.1 / 25.1) | 66.8 | 38.2 | −34.4 | 49.5 |
| 0.9 | 30.7 (55.9 / 25.2) | 73.3 | 45.9 | −37.9 | 41.5 | 26.4 (54.6 / 28.3) | 67.4 | 38.2 | −45.6 | 45.5 |
| Lockbox | Data | System tested | Status |
|---|---|---|---|
| 1 | WebQSP test Yih et al., 2016 , CWQ test Talmor and Berant,2018 | first version (first selector, lenient matching rule) | mixed; scored with a rule later found lenient, so not used as evidence ( Section G.1 ) |
| 2 | Mintaka test ( Sen et al., 2022 ; entity answers, 2,432 questions), QALD-10 test ( Usbeck et al., 2024 ; 171) with Wikidata 1-hop context | v2 (earlier selector) | failed; reported in Section G.2 |
| 3 | ClashEval ( Wu et al., 2024 ; 10,942 records: 1,247 original contexts, 9,695 perturbed, all perturbation levels); Housing Statute QA ( Zheng et al., 2025 ; 1,000 yes/no questions, BM25 retrieval within the state) | v2 as preregistered; v3 added by an amendment written before any output was read | Section 7.2 |
| Lockbox | File (first 16 hex digits of its SHA-256) | Frozen at |
|---|---|---|
| 1 | PREREGISTRATION_LOCKBOX.json ( 5847cc03f7a51f05 ) | 2026-10-06 |
| 2 | PREREGISTRATION_LOCKBOX2_SELECTION.json ( 22afe8ac578b90d5 ), PREREGISTRATION_LOCKBOX2_SYSTEM.json ( 4a9155d8dfb18bc4 ) | 2026-10-06 (selection), 2026-10-07 (system) |
| 3 | PREREGISTRATION_LOCKBOX3.json ( c10d51bf9086bea1 ) | 2026-10-08 01:28 |
| 3, amendment 1 | PREREGISTRATION_LOCKBOX3_AMENDMENT1.json ( 2c07407ff7150c2e ) | 2026-10-08 23:02 |
| Frozen artefact | SHA-256 (first 16 hex digits) |
|---|---|
| note policy, Qwen / Llama | 51e21f66c4754f5a / b96f56c4b6232bd4 |
| selector v2, Qwen / Llama | 53c8ccb97d90374d / cbf7f684c7b6fd68 |
| selector v3, Qwen / Llama | 60831c3e75732a59 / c2121e95254bd208 |
| selector v4, Qwen / Llama | 3358115d6a4d9766 / b9a0b3a7d5a4ecff |
| Setting | Model knowledge (closed-book) | Context | Ours against the best alternative |
|---|---|---|---|
| GRACE broken / wrong_branch / competing | useful (about 40% correct) | missing, wrong or contradictory | large gain |
| ClashEval names, years, locations, perturbed | useful | wrong | gain |
| GRACE clean; ClashEval original | useful | right | small cost at low π; parity at high π (Qwen) |
| GRACE-QT (rank, qualified, string) | poor (C−W about −33) | right, unperturbed | parity |
| Housing statutes | harmful (60% wrong) | partly retrieved, right | Qwen: below the plain reader at the registered π, near it at high π. Llama: the frozen reader does not answer yes/no; ties the plain reader, 15–23 points below free-text methods |
| ClashEval drug dosages | poor (closed-book wrong on 56–58% of answered questions) | wrong | reduced error rate with Qwen, no low-risk operating point |
| Situation in a deployed system | What goes wrong today | Evidence in this paper |
|---|---|---|
| Knowledge graph or index with missing facts (incomplete extraction, an entity not yet linked) | the reader abstains or answers from a partial path although the model knows the fact | GRACE broken: +6.9 (Qwen) and +5.9 (Llama) over the plain reader; the correct answer is visible in the output on 78.8% and 72.9% of records against 44.4% and 51.4% |
| Retrieved fact is wrong (extraction error, outdated or edited document, poisoned source) | the reader repeats the wrong fact with no sign of doubt | GRACE wrong_branch: unwarned wrong answers fall from 69.2% to 11.1% (Qwen) and from 26.4% to 14.1% (Llama); ClashEval perturbed documents: +35.6 (Qwen) and +16.4 (Llama) over the plain reader |
| Sources disagree with each other (two documents, two graph branches) | the reader picks one silently | GRACE competing: +8.1 (Qwen) and +7.1 (Llama); the conflict is stated on 38.8% and 30.5% of records |
| Mixed traffic, reliability of the context unknown per query | a context-following system and a memory-first system each fail on one side | one system, one parameter: the total is flat for π between 0.1 and 0.5 on GRACE (Section 7.1 ), and π = 0.99 returns to context-following behaviour |
| Task | A real question, wrong fact in the context | Plain reader | Ours | Wrong fact in context: ours − plain reader (Qwen / Llama) | Missing fact: ours − plain reader (Qwen / Llama) |
|---|---|---|---|---|---|
| Biographical lookup (father, education, award, adviser; 139 questions) | "What award did John Steinbeck receive?" The context says Alabama Hall of Fame . | "Alabama Hall of Fame" | "According to the provided information, … the Alabama Hall of Fame. As far as I know, John Steinbeck received the Nobel Prize in Literature" | +77.0 [62.6, 92.1] / +14.4 [3.6, 25.2] | +8.6 [0.0, 17.3] / +8.6 [−2.9, 20.1] |
| Geographic and administrative facts (capital, continent, located in, borders; 71) | "Which state of Australia has Melbourne as its capital?" The context says Western Australia . | "Western Australia" | "… As far as I know, this is incorrect; Melbourne is the capital of the state of Victoria" | +76.1 [53.5, 98.6] / +21.1 [5.6, 36.6] | +21.1 [9.9, 32.4] / +4.2 [−8.5, 18.3] |
| Attribution of works and discoveries (author, composer, inventor, developer; 71) | "Who is the writer of The Double Helix?" The context says Vladimir Lenin . | "Vladimir Lenin" | "… As far as I am confident, James Watson is the actual author of The Double Helix" | +95.8 [74.6, 116.9] / +21.1 [5.6, 36.6] | +5.6 [−7.0, 16.9] / −1.4 [−18.3, 15.5] |
| Organisations: ownership, membership, leadership (owner, founder, member of, chief executive; 56) | "Who is the business owner of Barbie the doll maker?" The context says United Parcel Service . | "United Parcel Service" | "… As far as I am confident, Mattel is the actual owner of Barbie, while United Parcel Service is a logistics company" | +87.5 [67.9, 107.1] / +10.7 [−5.4, 26.8] | −3.6 [−17.9, 8.9] / +17.9 [1.8, 35.7] |
| Problem | What the literature reports | Relation to our results |
|---|---|---|
| Answers on search engines (AI overviews, answer engines) | With a commercial search engine about 70% of retrieved passages lack the answer, and in conflicts the model is right 47.4% of the time (Astute RAG; Wang et al., ACL 2025). 57.2% of real questions retrieve contradicting web paragraphs Yuan et al., 2026 . A deployed system repeated a joke and a satire page as advice (Section 1 ). | Directly tested: ClashEval is built from web documents with perturbed answers (Section 7.2 ); misinformation, insufficient context and conflicting sources are the wrong_branch, broken and competing states of GRACE |
| Assistants and question answering over knowledge graphs | Knowledge graphs are incomplete and contain wrong statements: over 70% of people in Freebase had no place of birth West et al., 2014 ; Wikidata has removed 76.5 million statements and deprecated 10 million Shenoy et al., 2022 . On CRAG, with mock web and knowledge-graph search, industry RAG systems answer 63% of questions without hallucination Yang et al., 2024 . | Directly tested: GRACE is this setting (Sections 4 and 7) |
| GraphRAG over graphs extracted by a language model | Extraction loses triples and context (Huang et al., IJCAI 2025). | Appendix S4 measures deployed GraphRAG-family systems on GRACE |
| Corpora and agent memories that others can write to | Five injected passages per question give about 90% attack success Zou et al., 2025 ; injecting records into an agent's memory through queries alone succeeds for more than 95% of injections (Dong et al., NeurIPS 2025). | Not a defence against a targeted attack; when the attacked fact is known to the model the conflict is stated (76.9% of wrong_branch records with Qwen) |
| Direction | What was tried | Result | Lesson |
|---|---|---|---|
| Graph-edit policy trained with reinforcement learning | a teacher LLM proposes edits to the context graph; a small policy accepts, rejects or stops | Acc3 50.3% against 51.1% for applying every edit | the reward gave nothing for a correct added edge that was not a gold edge, so stopping early was always safe; the policy discarded useful knowledge |
| Self-verification as a filter | each proposed triple is scored alone by the LLM (AUC 0.875 on 800 held-out facts); rejected triples are deleted | 50.4%, equal to deleting the same number of triples at random (50.6%) | the model knows which facts are false, but deleting a false fact with no replacement removes the relation and the reader answers "insufficient" (27 of 29 harmed wrong_branch cases) |
| Verify, then repair | a rejected object is refilled from the model's knowledge and re-verified; never delete without a replacement | +4.8 to +6.8 Acc3 over the plain reader on two fresh slices | useful, but the context is edited, and stale knowledge can overwrite a correct, newer fact |
| Confidence tags on context facts | each context fact annotated with the model's belief (three wordings) | −1.4 to −4.4 Acc3 on every slice | 14% of correct facts receive a low score; a low score mixes "unfamiliar" with "false", and the reader then ignores correct facts |
| Gates on a "does the model know" signal (WebQSP / CWQ validation) | answer from memory when a signal passes a threshold | C−W stayed near 27 | the best single signal reaches AUC 0.78 (agreement over five samples 0.73, minimum token probability 0.78, linear probe on the last hidden layer 0.76); a gate also hides the knowledge |
| Attention-based selector | candidates, notes and facts as tokens; softmax over candidates and "none" | C−W 37.6 against 48.2 for gradient boosting (Qwen, earlier scoring rule) | with 3,600 records the transformer does not learn which note supports which candidate; the softmax spreads probability so the cautious mode abstains too often |
Knowledge Conflicts in Language Models
Knowledge conflicts in language models concern how models reconcile stored knowledge with conflicting context, retrieved evidence, tools, or memory.
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