论文标题
用分层替代规则集的机器学习模型行为的视觉探索
Visual Exploration of Machine Learning Model Behavior with Hierarchical Surrogate Rule Sets
论文作者
论文摘要
模型解释的潜在解决方案之一是训练替代模型:一个更透明的模型,该模型近似于要解释的模型的行为。通常,由于其基于逻辑的表达式的清晰度,使用分类规则或决策树。但是,决策树可能会长得太深,规则集可能变得太大,无法近似复杂的模型。与必须共享祖先节点(条件)的决策树上的路径不同,规则更灵活。但是,规则的非结构化视觉表示使得很难跨规则进行推断。为了解决这些问题,我们提出了一个工作流,其中包括新型算法和交互式解决方案。首先,我们提出分层替代规则(HSR),该算法基于用户定义的参数生成层次规则。我们还可以肯定,这是一个整合HSR和交互式替代规则可视化的视觉分析系统(VA)系统。特别是,我们提出了一棵新颖的特征对树,以克服现有规则可视化的缺点。我们从参数敏感性,时间性能和与替代决策树的比较方面评估了算法,并发现它可以很好地缩放,并且在许多方面都超过了决策树的表现。我们还通过一项可用性研究评估了24名志愿者的可用性研究和VA系统,并与7个领域专家进行了观察性研究。我们的调查表明,参与者可以使用与特征对齐的树木以非常高的精度执行非平凡的任务。我们还讨论了许多有趣的观察结果,这些观察对于设计有效的基于规则的VA系统的未来研究很有用。
One of the potential solutions for model interpretation is to train a surrogate model: a more transparent model that approximates the behavior of the model to be explained. Typically, classification rules or decision trees are used due to the intelligibility of their logic-based expressions. However, decision trees can grow too deep and rule sets can become too large to approximate a complex model. Unlike paths on a decision tree that must share ancestor nodes (conditions), rules are more flexible. However, the unstructured visual representation of rules makes it hard to make inferences across rules. To address these issues, we present a workflow that includes novel algorithmic and interactive solutions. First, we present Hierarchical Surrogate Rules (HSR), an algorithm that generates hierarchical rules based on user-defined parameters. We also contribute SuRE, a visual analytics (VA) system that integrates HSR and interactive surrogate rule visualizations. Particularly, we present a novel feature-aligned tree to overcome the shortcomings of existing rule visualizations. We evaluate the algorithm in terms of parameter sensitivity, time performance, and comparison with surrogate decision trees and find that it scales reasonably well and outperforms decision trees in many respects. We also evaluate the visualization and the VA system by a usability study with 24 volunteers and an observational study with 7 domain experts. Our investigation shows that the participants can use feature-aligned trees to perform non-trivial tasks with very high accuracy. We also discuss many interesting observations that can be useful for future research on designing effective rule-based VA systems.