Cherry-Picking in Time Series Forecasting: How to Select Datasets to Make Your Model Shine

Fuente: arXiv
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Main Authors: Roque, Luis, Soares, Carlos, Cerqueira, Vitor, Torgo, Luis
Format: Preprint
Published: 2024
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author Roque, Luis
Soares, Carlos
Cerqueira, Vitor
Torgo, Luis
author_facet Roque, Luis
Soares, Carlos
Cerqueira, Vitor
Torgo, Luis
contents The importance of time series forecasting drives continuous research and the development of new approaches to tackle this problem. Typically, these methods are introduced through empirical studies that frequently claim superior accuracy for the proposed approaches. Nevertheless, concerns are rising about the reliability and generalizability of these results due to limitations in experimental setups. This paper addresses a critical limitation: the number and representativeness of the datasets used. We investigate the impact of dataset selection bias, particularly the practice of cherry-picking datasets, on the performance evaluation of forecasting methods. Through empirical analysis with a diverse set of benchmark datasets, our findings reveal that cherry-picking datasets can significantly distort the perceived performance of methods, often exaggerating their effectiveness. Furthermore, our results demonstrate that by selectively choosing just four datasets - what most studies report - 46% of methods could be deemed best in class, and 77% could rank within the top three. Additionally, recent deep learning-based approaches show high sensitivity to dataset selection, whereas classical methods exhibit greater robustness. Finally, our results indicate that, when empirically validating forecasting algorithms on a subset of the benchmarks, increasing the number of datasets tested from 3 to 6 reduces the risk of incorrectly identifying an algorithm as the best one by approximately 40%. Our study highlights the critical need for comprehensive evaluation frameworks that more accurately reflect real-world scenarios. Adopting such frameworks will ensure the development of robust and reliable forecasting methods.
format Preprint
id arxiv_https___arxiv_org_abs_2412_14435
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Cherry-Picking in Time Series Forecasting: How to Select Datasets to Make Your Model Shine
Roque, Luis
Soares, Carlos
Cerqueira, Vitor
Torgo, Luis
Machine Learning
Artificial Intelligence
68T01
I.5.1; G.3; H.2.8; I.2.1
The importance of time series forecasting drives continuous research and the development of new approaches to tackle this problem. Typically, these methods are introduced through empirical studies that frequently claim superior accuracy for the proposed approaches. Nevertheless, concerns are rising about the reliability and generalizability of these results due to limitations in experimental setups. This paper addresses a critical limitation: the number and representativeness of the datasets used. We investigate the impact of dataset selection bias, particularly the practice of cherry-picking datasets, on the performance evaluation of forecasting methods. Through empirical analysis with a diverse set of benchmark datasets, our findings reveal that cherry-picking datasets can significantly distort the perceived performance of methods, often exaggerating their effectiveness. Furthermore, our results demonstrate that by selectively choosing just four datasets - what most studies report - 46% of methods could be deemed best in class, and 77% could rank within the top three. Additionally, recent deep learning-based approaches show high sensitivity to dataset selection, whereas classical methods exhibit greater robustness. Finally, our results indicate that, when empirically validating forecasting algorithms on a subset of the benchmarks, increasing the number of datasets tested from 3 to 6 reduces the risk of incorrectly identifying an algorithm as the best one by approximately 40%. Our study highlights the critical need for comprehensive evaluation frameworks that more accurately reflect real-world scenarios. Adopting such frameworks will ensure the development of robust and reliable forecasting methods.
title Cherry-Picking in Time Series Forecasting: How to Select Datasets to Make Your Model Shine
topic Machine Learning
Artificial Intelligence
68T01
I.5.1; G.3; H.2.8; I.2.1
url https://arxiv.org/abs/2412.14435