Sub-national governments across the United States implement a variety of policies to address large societal problems and needs. Many policies are picked up or adopted in other states. This process is called policy diffusion and allows researchers to analyze and compare social, political, and contextual characteristics that lead to adopting certain policies, as well as the efficacy of these policies once adopted. In this paper, we introduce PDViz, a visual analytics approach for social scientists to dynamically analyze the policy diffusion history and underlying patterns. It is designed for analyzing and answering a list of research questions and tasks posed by social scientists in prior work. To evaluate our system, we present two usage scenarios and conduct interviews with domain experts in political science. The interviews highlight that PDViz provides the result of policy diffusion patterns that align with their domain knowledge as well as the potential to be a learning tool for students and researchers to understand the concept of policy diffusion.

翻译：美国各州政府实施多种政策以应对重大社会问题和需求。许多政策被其他州采纳或借鉴。这一过程被称为政策扩散，使研究人员能够分析并比较导致特定政策采纳的社会、政治及情境特征，以及这些政策在采纳后的有效性。本文介绍了一种名为PDViz的可视分析方法，使社会科学家能够动态分析政策扩散的历史及其潜在模式。该方法旨在分析与回答社会科学人员在先前研究中提出的一系列研究问题与任务。为评估我们的系统，我们展示了两个使用场景，并对政治学领域的领域专家进行了访谈。访谈结果表明，PDViz提供的政策扩散模式结果与其领域知识相契合，同时具备成为学生和研究人员理解政策扩散概念学习工具的潜力。