From Zero to Hero: Cold-Start Anomaly Detection

Tal Reiss, George Kour, Naama Zwerdling, Ateret Anaby Tavor, Yedid Hoshen


Abstract
When first deploying an anomaly detection system, e.g., to detect out-of-scope queries in chatbots, there are no observed data, making data-driven approaches ineffective. Zero-shot anomaly detection methods offer a solution to such “cold-start” cases, but unfortunately they are often not accurate enough. This paper studies the realistic but underexplored cold-start setting where an anomaly detection model is initialized using zero-shot guidance, but subsequently receives a small number of contaminated observations (namely, that may include anomalies). The goal is to make efficient use of both the zero-shot guidance and the observations. We propose ColdFusion, a method that effectively adapts the zero-shot anomaly detector to contaminated observations. To support future development of this new setting, we propose an evaluation suite consisting of evaluation protocols and metrics.
Anthology ID:
2024.findings-acl.453
Volume:
Findings of the Association for Computational Linguistics ACL 2024
Month:
August
Year:
2024
Address:
Bangkok, Thailand and virtual meeting
Editors:
Lun-Wei Ku, Andre Martins, Vivek Srikumar
Venue:
Findings
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
7607–7617
Language:
URL:
https://aclanthology.org/2024.findings-acl.453
DOI:
Bibkey:
Cite (ACL):
Tal Reiss, George Kour, Naama Zwerdling, Ateret Anaby Tavor, and Yedid Hoshen. 2024. From Zero to Hero: Cold-Start Anomaly Detection. In Findings of the Association for Computational Linguistics ACL 2024, pages 7607–7617, Bangkok, Thailand and virtual meeting. Association for Computational Linguistics.
Cite (Informal):
From Zero to Hero: Cold-Start Anomaly Detection (Reiss et al., Findings 2024)
Copy Citation:
PDF:
https://aclanthology.org/2024.findings-acl.453.pdf