Multilayer networks have been widely used to represent and analyze systems of interconnected entities where both the entities and their connections can be of different types. However, real multilayer networks can be difficult to analyze because of irrelevant information, such as layers not related to the objective of the analysis, because of their size, or because traditional methods defined to analyze simple networks do not have a straightforward extension able to handle multiple layers. Therefore, a number of methods have been devised in the literature to simplify multilayer networks with the objective of improving our ability to analyze them. In this article we provide a unified and practical taxonomy of existing simplification approaches, and we identify categories of multilayer network simplification methods that are still underdeveloped, as well as emerging trends.

多层网络已被广泛用于表示和分析互连实体的系统，其中实体及其连接都可以是不同类型。但是，由于不相关的信息（例如与分析目标不相关的层），由于其大小或定义用于分析简单网络的传统方法没有能够处理的简单扩展，因此，实际的多层网络可能难以分析。多层。因此，文献中已经设计出许多方法来简化多层网络，旨在提高我们的分析能力。在本文中，我们提供了现有简化方法的统一且实用的分类法，并确定了仍在开发中的多层网络简化方法的类别以及新兴趋势。