The University of Southampton
University of Southampton Institutional Repository

NLP verification: towards a general methodology for certifying robustness

NLP verification: towards a general methodology for certifying robustness
NLP verification: towards a general methodology for certifying robustness

Machine learning has exhibited substantial success in the field of natural language processing (NLP). For example, large language models have empirically proven to be capable of producing text of high complexity and cohesion. However, at the same time, they are prone to inaccuracies and hallucinations. As these systems are increasingly integrated into real-world applications, ensuring their safety and reliability becomes a primary concern. There are safety critical contexts where such models must be robust to variability or attack and give guarantees over their output. Computer vision had pioneered the use of formal verification of neural networks for such scenarios and developed common verification standards and pipelines, leveraging precise formal reasoning about geometric properties of data manifolds. In contrast, NLP verification methods have only recently appeared in the literature. While presenting sophisticated algorithms in their own right, these papers have not yet crystallised into a common methodology. They are often light on the pragmatical issues of NLP verification, and the area remains fragmented. In this paper, we attempt to distil and evaluate general components of an NLP verification pipeline that emerges from the progress in the field to date. Our contributions are twofold. First, we propose a general methodology to analyse the effect of the embedding gap - a problem that refers to the discrepancy between verification of geometric subspaces, and the semantic meaning of sentences which the geometric subspaces are supposed to represent. We propose a number of practical NLP methods that can help to quantify the effects of the embedding gap. Second, we give a general method for training and verification of neural networks that leverages a more precise geometric estimation of semantic similarity of sentences in the embedding space and helps to overcome the effects of the embedding gap in practice.

adversarial training, machine learning, natural language processing, Neural networks, robustness, verification
0956-7925
Casadio, Marco
f32f79ab-7e18-4ed0-bc17-8988a2b7786c
Dinkar, Tanvi
a54bfc2a-2b2a-485a-8639-6bb7185a93ac
Komendantskaya, Ekaterina
f12d9c23-5589-40b8-bcf9-a04fe9dedf61
Arnaboldi, Luca
b7ba4883-52bd-4950-b63d-2e993c951b5b
Daggitt, Matthew L.
7788a0b1-f07e-4b37-b34a-77b7d6ad4005
Isac, Omri
c7b07a87-a81f-422f-b367-b256879b5a46
Katz, Guy
0d2bbdb4-3a24-482d-822d-bf8336f92500
Rieser, Verena
46a9e502-2839-46c8-bfd9-096ad5f4f3a8
Lemon, Oliver
806a87ea-f2bd-44c2-acfa-52bf0ea07784
Casadio, Marco
f32f79ab-7e18-4ed0-bc17-8988a2b7786c
Dinkar, Tanvi
a54bfc2a-2b2a-485a-8639-6bb7185a93ac
Komendantskaya, Ekaterina
f12d9c23-5589-40b8-bcf9-a04fe9dedf61
Arnaboldi, Luca
b7ba4883-52bd-4950-b63d-2e993c951b5b
Daggitt, Matthew L.
7788a0b1-f07e-4b37-b34a-77b7d6ad4005
Isac, Omri
c7b07a87-a81f-422f-b367-b256879b5a46
Katz, Guy
0d2bbdb4-3a24-482d-822d-bf8336f92500
Rieser, Verena
46a9e502-2839-46c8-bfd9-096ad5f4f3a8
Lemon, Oliver
806a87ea-f2bd-44c2-acfa-52bf0ea07784

Casadio, Marco, Dinkar, Tanvi, Komendantskaya, Ekaterina, Arnaboldi, Luca, Daggitt, Matthew L., Isac, Omri, Katz, Guy, Rieser, Verena and Lemon, Oliver (2025) NLP verification: towards a general methodology for certifying robustness. European Journal of Applied Mathematics. (doi:10.1017/S0956792525000099).

Record type: Article

Abstract

Machine learning has exhibited substantial success in the field of natural language processing (NLP). For example, large language models have empirically proven to be capable of producing text of high complexity and cohesion. However, at the same time, they are prone to inaccuracies and hallucinations. As these systems are increasingly integrated into real-world applications, ensuring their safety and reliability becomes a primary concern. There are safety critical contexts where such models must be robust to variability or attack and give guarantees over their output. Computer vision had pioneered the use of formal verification of neural networks for such scenarios and developed common verification standards and pipelines, leveraging precise formal reasoning about geometric properties of data manifolds. In contrast, NLP verification methods have only recently appeared in the literature. While presenting sophisticated algorithms in their own right, these papers have not yet crystallised into a common methodology. They are often light on the pragmatical issues of NLP verification, and the area remains fragmented. In this paper, we attempt to distil and evaluate general components of an NLP verification pipeline that emerges from the progress in the field to date. Our contributions are twofold. First, we propose a general methodology to analyse the effect of the embedding gap - a problem that refers to the discrepancy between verification of geometric subspaces, and the semantic meaning of sentences which the geometric subspaces are supposed to represent. We propose a number of practical NLP methods that can help to quantify the effects of the embedding gap. Second, we give a general method for training and verification of neural networks that leverages a more precise geometric estimation of semantic similarity of sentences in the embedding space and helps to overcome the effects of the embedding gap in practice.

Text
nlp-verification-towards-a-general-methodology-for-certifying-robustness - Version of Record
Available under License Creative Commons Attribution.
Download (1MB)

More information

Accepted/In Press date: 18 February 2025
e-pub ahead of print date: 2 April 2025
Published date: 2 April 2025
Additional Information: Publisher Copyright: © The Author(s), 2025. Published by Cambridge University Press.
Keywords: adversarial training, machine learning, natural language processing, Neural networks, robustness, verification

Identifiers

Local EPrints ID: 500801
URI: http://eprints.soton.ac.uk/id/eprint/500801
ISSN: 0956-7925
PURE UUID: 79cbc5d2-660f-40e0-bb20-be9eeebefb40
ORCID for Ekaterina Komendantskaya: ORCID iD orcid.org/0000-0002-3240-0987

Catalogue record

Date deposited: 13 May 2025 16:55
Last modified: 30 Aug 2025 02:14

Export record

Altmetrics

Contributors

Author: Marco Casadio
Author: Tanvi Dinkar
Author: Ekaterina Komendantskaya ORCID iD
Author: Luca Arnaboldi
Author: Matthew L. Daggitt
Author: Omri Isac
Author: Guy Katz
Author: Verena Rieser
Author: Oliver Lemon

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×