Evaluation of Stress Detection as Time Series Events -- A Novel Window-Based F1-Metric

Fuente: arXiv
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Main Authors: Skat-Rørdam, Harald Vilhelm, Das, Sneha, Rasmussen, Kathrine Sofie, Lønfeldt, Nicole Nadine, Clemmensen, Line
Format: Preprint
Published: 2025
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author Skat-Rørdam, Harald Vilhelm
Das, Sneha
Rasmussen, Kathrine Sofie
Lønfeldt, Nicole Nadine
Clemmensen, Line
author_facet Skat-Rørdam, Harald Vilhelm
Das, Sneha
Rasmussen, Kathrine Sofie
Lønfeldt, Nicole Nadine
Clemmensen, Line
contents Accurate evaluation of event detection in time series is essential for applications such as stress monitoring with wearable devices, where ground truth is typically annotated as single-point events, even though the underlying phenomena are gradual and temporally diffused. Standard metrics like F1 and point-adjusted F1 (F1$_{pa}$) often misrepresent model performance in such real-world, imbalanced datasets. We introduce a window-based F1 metric (F1$_w$) that incorporates temporal tolerance, enabling a more robust assessment of event detection when exact alignment is unrealistic. Empirical analysis in three physiological datasets, two in-the-wild (ADARP, Wrist Angel) and one experimental (ROAD), indicates that F1$_w$ reveals meaningful model performance patterns invisible to conventional metrics, while its window size can be adapted to domain knowledge to avoid overestimation. We show that the choice of evaluation metric strongly influences the interpretation of model performance: using predictions from TimesFM, only our temporally tolerant metrics reveal statistically significant improvements over random and null baselines in the two in-the-wild use cases. This work addresses key gaps in time series evaluation and provides practical guidance for healthcare applications where requirements for temporal precision vary by context.
format Preprint
id arxiv_https___arxiv_org_abs_2509_03240
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Evaluation of Stress Detection as Time Series Events -- A Novel Window-Based F1-Metric
Skat-Rørdam, Harald Vilhelm
Das, Sneha
Rasmussen, Kathrine Sofie
Lønfeldt, Nicole Nadine
Clemmensen, Line
Machine Learning
Artificial Intelligence
Methodology
Accurate evaluation of event detection in time series is essential for applications such as stress monitoring with wearable devices, where ground truth is typically annotated as single-point events, even though the underlying phenomena are gradual and temporally diffused. Standard metrics like F1 and point-adjusted F1 (F1$_{pa}$) often misrepresent model performance in such real-world, imbalanced datasets. We introduce a window-based F1 metric (F1$_w$) that incorporates temporal tolerance, enabling a more robust assessment of event detection when exact alignment is unrealistic. Empirical analysis in three physiological datasets, two in-the-wild (ADARP, Wrist Angel) and one experimental (ROAD), indicates that F1$_w$ reveals meaningful model performance patterns invisible to conventional metrics, while its window size can be adapted to domain knowledge to avoid overestimation. We show that the choice of evaluation metric strongly influences the interpretation of model performance: using predictions from TimesFM, only our temporally tolerant metrics reveal statistically significant improvements over random and null baselines in the two in-the-wild use cases. This work addresses key gaps in time series evaluation and provides practical guidance for healthcare applications where requirements for temporal precision vary by context.
title Evaluation of Stress Detection as Time Series Events -- A Novel Window-Based F1-Metric
topic Machine Learning
Artificial Intelligence
Methodology
url https://arxiv.org/abs/2509.03240