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：美国各州政府为解决重大社会问题和需求，实施了一系列政策。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被采纳的社会、政治及情境特征，以及政策采纳后的有效性。本文介绍了PDViz，一种面向社会科学家的可视分析方法，用于动态分析政策扩散历史及其潜在模式。该方法旨在回应并解答社会科学工作者在先前研究中提出的一系列研究问题与任务。为评估系统性能，我们呈现了两个使用场景，并对政治学领域的专家进行了访谈。访谈结果表明，PDViz能够提供与其领域知识相符的政策扩散模式分析结果，并具有成为学生及研究人员理解政策扩散概念的学习工具的潜力。