A Glitch in the Matrix? Locating and Detecting Language Model Grounding with Fakepedia

Fuente: arXiv
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Auteurs principaux: Monea, Giovanni, Peyrard, Maxime, Josifoski, Martin, Chaudhary, Vishrav, Eisner, Jason, Kıcıman, Emre, Palangi, Hamid, Patra, Barun, West, Robert
Format: Preprint
Publié: 2023
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author Monea, Giovanni
Peyrard, Maxime
Josifoski, Martin
Chaudhary, Vishrav
Eisner, Jason
Kıcıman, Emre
Palangi, Hamid
Patra, Barun
West, Robert
author_facet Monea, Giovanni
Peyrard, Maxime
Josifoski, Martin
Chaudhary, Vishrav
Eisner, Jason
Kıcıman, Emre
Palangi, Hamid
Patra, Barun
West, Robert
contents Large language models (LLMs) have an impressive ability to draw on novel information supplied in their context. Yet the mechanisms underlying this contextual grounding remain unknown, especially in situations where contextual information contradicts factual knowledge stored in the parameters, which LLMs also excel at recalling. Favoring the contextual information is critical for retrieval-augmented generation methods, which enrich the context with up-to-date information, hoping that grounding can rectify outdated or noisy stored knowledge. We present a novel method to study grounding abilities using Fakepedia, a novel dataset of counterfactual texts constructed to clash with a model's internal parametric knowledge. In this study, we introduce Fakepedia, a counterfactual dataset designed to evaluate grounding abilities when the internal parametric knowledge clashes with the contextual information. We benchmark various LLMs with Fakepedia and conduct a causal mediation analysis of LLM components when answering Fakepedia queries, based on our Masked Grouped Causal Tracing (MGCT) method. Through this analysis, we identify distinct computational patterns between grounded and ungrounded responses. We finally demonstrate that distinguishing grounded from ungrounded responses is achievable through computational analysis alone. Our results, together with existing findings about factual recall mechanisms, provide a coherent narrative of how grounding and factual recall mechanisms interact within LLMs.
format Preprint
id arxiv_https___arxiv_org_abs_2312_02073
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle A Glitch in the Matrix? Locating and Detecting Language Model Grounding with Fakepedia
Monea, Giovanni
Peyrard, Maxime
Josifoski, Martin
Chaudhary, Vishrav
Eisner, Jason
Kıcıman, Emre
Palangi, Hamid
Patra, Barun
West, Robert
Computation and Language
Artificial Intelligence
Machine Learning
Large language models (LLMs) have an impressive ability to draw on novel information supplied in their context. Yet the mechanisms underlying this contextual grounding remain unknown, especially in situations where contextual information contradicts factual knowledge stored in the parameters, which LLMs also excel at recalling. Favoring the contextual information is critical for retrieval-augmented generation methods, which enrich the context with up-to-date information, hoping that grounding can rectify outdated or noisy stored knowledge. We present a novel method to study grounding abilities using Fakepedia, a novel dataset of counterfactual texts constructed to clash with a model's internal parametric knowledge. In this study, we introduce Fakepedia, a counterfactual dataset designed to evaluate grounding abilities when the internal parametric knowledge clashes with the contextual information. We benchmark various LLMs with Fakepedia and conduct a causal mediation analysis of LLM components when answering Fakepedia queries, based on our Masked Grouped Causal Tracing (MGCT) method. Through this analysis, we identify distinct computational patterns between grounded and ungrounded responses. We finally demonstrate that distinguishing grounded from ungrounded responses is achievable through computational analysis alone. Our results, together with existing findings about factual recall mechanisms, provide a coherent narrative of how grounding and factual recall mechanisms interact within LLMs.
title A Glitch in the Matrix? Locating and Detecting Language Model Grounding with Fakepedia
topic Computation and Language
Artificial Intelligence
Machine Learning
url https://arxiv.org/abs/2312.02073