论文标题
基于语言的因果代表学习
Language-Based Causal Representation Learning
论文作者
论文摘要
考虑由一个简单,离散的动力学系统产生的有限状态图,在该系统中,代理在矩形网格拾取和删除软件包中移动。问题的状态变量(即,代理位置和软件包位置)是否可以单独从状态图的结构中恢复,而无需访问有关对象,状态结构或任何背景知识的信息?我们表明,这是可能的,只要动力学是通过与域无关的一阶因果语言学习的,这为对象和关系提供了空间,而这些关系的空间是尚不清楚的。与数据兼容的语言中最紧凑的表示的偏爱提供了强大而有意义的学习偏见,从而使这一偏见成为可能。结构化因果模型(SCM)的语言是代表(静态)因果模型的标准语言,但在由对象填充的动态世界中,需要诸如“经典AI计划”中使用的一阶因果语言。虽然“经典AI”需要手工制作的表示,但可以通过相同语言从非结构化数据中学到类似的表示形式。的确,在那些语言中,语言和对紧凑型表示的偏好为世界提供了结构,揭示了对象,关系和原因。
Consider the finite state graph that results from a simple, discrete, dynamical system in which an agent moves in a rectangular grid picking up and dropping packages. Can the state variables of the problem, namely, the agent location and the package locations, be recovered from the structure of the state graph alone without having access to information about the objects, the structure of the states, or any background knowledge? We show that this is possible provided that the dynamics is learned over a suitable domain-independent first-order causal language that makes room for objects and relations that are not assumed to be known. The preference for the most compact representation in the language that is compatible with the data provides a strong and meaningful learning bias that makes this possible. The language of structured causal models (SCMs) is the standard language for representing (static) causal models but in dynamic worlds populated by objects, first-order causal languages such as those used in "classical AI planning" are required. While "classical AI" requires handcrafted representations, similar representations can be learned from unstructured data over the same languages. Indeed, it is the languages and the preference for compact representations in those languages that provide structure to the world, uncovering objects, relations, and causes.