论文标题
在存在稀疏面前检测概念漂移 - 自动变更风险评估系统的案例研究
Detecting Concept Drift in the Presence of Sparsity -- A Case Study of Automated Change Risk Assessment System
论文作者
论文摘要
在文献中被广泛称为\ textit {sparsity}的缺失值是许多现实世界数据集的共同特征。已经提出了许多插补方法来解决这个数据不完整或稀疏性问题。但是,对于给定功能或数据集中的一组功能,数据插补方法的准确性高度取决于特征值的分布及其与其他功能的相关性。困扰着机器学习(ML)解决方案行业部署的另一个问题是概念漂移检测,在缺少价值观的情况下,这变得更具挑战性。尽管已经对数据插图和概念漂移检测进行了广泛的研究,但很少有工作尝试合并研究这两种现象,即在存在稀疏性的情况下,概念漂移检测。在这项工作中,我们对以下各项进行了系统的研究:(i)缺失值的不同模式,(ii)用于不同种类的稀疏性的各种统计和基于ML的数据插入方法,(iii)几种概念漂移检测方法,(iv)对基于缺失值的最佳数据选择的各种概念检测指标的各种概念检测指标的实际分析,(iv)。我们首先将其分析在合成数据和公开可用数据集上,并最终将发现扩展到我们已部署的自动变更风险评估系统的解决方案。我们的实证研究的主要发现之一是在所有相关指标中缺乏任何一种概念漂移检测方法的至高无上。因此,我们采用基于多数投票的概念漂移探测器的集合来突然和逐渐概念漂移。我们的实验表明,在所有指标中,这种集合方法可以实现最佳或接近最佳的性能。
Missing values, widely called as \textit{sparsity} in literature, is a common characteristic of many real-world datasets. Many imputation methods have been proposed to address this problem of data incompleteness or sparsity. However, the accuracy of a data imputation method for a given feature or a set of features in a dataset is highly dependent on the distribution of the feature values and its correlation with other features. Another problem that plagues industry deployments of machine learning (ML) solutions is concept drift detection, which becomes more challenging in the presence of missing values. Although data imputation and concept drift detection have been studied extensively, little work has attempted a combined study of the two phenomena, i.e., concept drift detection in the presence of sparsity. In this work, we carry out a systematic study of the following: (i) different patterns of missing values, (ii) various statistical and ML based data imputation methods for different kinds of sparsity, (iii) several concept drift detection methods, (iv) practical analysis of the various drift detection metrics, (v) selecting the best concept drift detector given a dataset with missing values based on the different metrics. We first analyze it on synthetic data and publicly available datasets, and finally extend the findings to our deployed solution of automated change risk assessment system. One of the major findings from our empirical study is the absence of supremacy of any one concept drift detection method across all the relevant metrics. Therefore, we adopt a majority voting based ensemble of concept drift detectors for abrupt and gradual concept drifts. Our experiments show optimal or near optimal performance can be achieved for this ensemble method across all the metrics.