论文标题
从低阶条件独立性中恢复因果结构
Recovering Causal Structures from Low-Order Conditional Independencies
论文作者
论文摘要
从数据学习因果模型的常见障碍之一是,随机变量之间的高阶条件独立性(CI)关系很难估算。由于即使对于少量观测值,也可以准确地执行具有低阶条件的CI测试,因此确定休闲结构的合理方法仅基于低阶CI。最近的研究证实,例如在稀疏的真实因果模型的情况下,甚至从零和一阶条件独立性中学到的结构产生了模型良好的近似值。但是,这里具有挑战性的任务是提供忠实地解释一组低阶顺式的方法。在本文中,我们提出了一种算法,该算法对于给定的有条件独立性的订单独立性较小或等于$ k $,其中$ k $是一个较小的固定数字,计算给定集的忠实图形表示。我们的结果完成并概括了以前从成对边际独立性学习的工作。此外,它们能够改进0-1图模型,例如大量用于基因组网络的估计。
One of the common obstacles for learning causal models from data is that high-order conditional independence (CI) relationships between random variables are difficult to estimate. Since CI tests with conditioning sets of low order can be performed accurately even for a small number of observations, a reasonable approach to determine casual structures is to base merely on the low-order CIs. Recent research has confirmed that, e.g. in the case of sparse true causal models, structures learned even from zero- and first-order conditional independencies yield good approximations of the models. However, a challenging task here is to provide methods that faithfully explain a given set of low-order CIs. In this paper, we propose an algorithm which, for a given set of conditional independencies of order less or equal to $k$, where $k$ is a small fixed number, computes a faithful graphical representation of the given set. Our results complete and generalize the previous work on learning from pairwise marginal independencies. Moreover, they enable to improve upon the 0-1 graph model which, e.g. is heavily used in the estimation of genome networks.