一句话:提出用元模型融合多种不确定性度量来预测误分类,从而对 DNN 测试输入进行优先级排序。
随着深度学习被用于安全关键领域,DNN 的系统化测试成为关乎人身安全的重要问题。由于 DNN 的数据驱动特性,测试有效性高度依赖测试数据集的充分性,而数据标注需要人工甚至专家知识。本文提出一种测试数据优先级排序方法:训练一个元模型,其输入是来自其他基模型输出的多种不确定性度量,通过融合不同度量来克服各自局限并适应更广的场景;元模型以「该测试输入是否会导致被测模型预测错误」为训练目标。作者在常用图像分类数据集和 DNN 模型上开展实验,并在包含与不包含分布外数据的两种设置下,从分布感知角度评估该方法。结果表明,该方法能有效对测试数据集排序,并优于参与比较的现有最先进测试优先级方法。
With the use of Deep Learning (DL) in safety-critical domains, the systematic testing of these systems has become a critical issue for human life. Due to the data-driven nature of Deep Neural Networks (DNNs), the effectiveness of tests is closely related to the adequacy of test datasets. Test data need to be labeled, which requires manual human effort and sometimes expert knowledge. DL system testers aim to select the test data that will be most helpful in identifying the weaknesses of the DNN model by using resources efficiently. To help achieve this goal, we propose a test data prioritization approach based on using a meta-model that gets uncertainty metrics as input, which are derived from outputs of other base models. Integrating different uncertainty metrics helps overcome individual limitations of these metrics and be effective in a wider range of scenarios. We train the meta-models with the objective of predicting whether a test input will lead the tested model to make an incorrect prediction or not. We conducted an experimental evaluation with popular image classification datasets and DNN models to evaluate the proposed approach. The results of the experiments demonstrate that our approach effectively prioritizes the test datasets and outperforms existing state-of-the-art test prioritization methods used in comparison. In the experiments, we evaluated the test prioritization approach from a distribution-aware perspective by generating test datasets with and without out-of-distribution data.