Much recent work has argued that the variation in the languages of the world can be explained from the perspective of efficient communication; in particular, languages can be seen as optimally balancing competing pressures to be simple and to be informative. Focusing on the expression of meaning -- semantic typology -- the present paper asks what factors are responsible for successful explanations in terms of efficient communication. Using the Information Bottleneck (IB) approach to formalizing this trade-off, we first demonstrate and analyze a correlation between optimality in the IB sense and a novel generalization of convexity to this setting. In a second experiment, we manipulate various modeling parameters in the IB framework to determine which factors drive the correlation between convexity and optimality. We find that the convexity of the communicative need distribution plays an especially important role. These results move beyond showing that efficient communication can explain aspects of semantic typology into explanations for why that is the case by identifying which underlying factors are responsible.

翻译：近期许多研究认为，世界语言的多样性可以从高效通信的角度得到解释；具体而言，语言可被视为在简洁性与信息性这两种竞争压力之间达到了最优平衡。本文聚焦于意义表达——语义类型学——探讨高效通信视角下的成功解释究竟由哪些因素决定。通过采用信息瓶颈方法形式化这一权衡关系，我们首先论证并分析了IB意义下的最优性与该情境中凸性的新型推广之间的相关性。在第二个实验中，我们通过调控IB框架中的各类建模参数，以确定哪些因素驱动着凸性与最优性之间的关联。研究发现，通信需求分布的凸性发挥着尤为关键的作用。这些成果不仅揭示了高效通信能够解释语义类型学的某些特征，更进一步通过识别其背后的驱动因素，阐明了产生这种现象的根本原因。