Using Locally Learnt Word Representations for better Textual Anomaly Detection
Alicia Breidenstein, Matthieu Labeau · 2024
The literature on general purpose textual Anomaly Detection is quite sparse, as most textual anomaly detection methods are implemented as out of domain detection in the context of pre-established classification tasks.Notably, in a field where pre-trained representations and models are of common use, the impact of the pre-training data on a task that lacks supervision has not been studied.In this paper, we use the simple setting of k-classes out anomaly detection and search for the best pairing of representation and classifier.We show that well-chosen embeddings allow a simple anomaly detection baseline such as OC-SVM to achieve similar results and even outperform deep state-of-the-art models.