The diffusion of disinformation via social media has become a pressing societal concern for business leaders and policy makers. In recent years, online disinformation has been implicated as a source of field-level institutional change across a variety of societal contexts. To better understand how online disinformation changes institutional issue fields, we explore how digital materiality affords users opportunities to create and propagate disinformation. We introduce and define three social media material features: modular content, content flow, and manifold network structures. From these digital materiality elements, we articulate three disinformation affordances: crafting, amplifying, and partitioning. We rely on several vignettes – far-right political conspiracy group, QAnon, anti-vaccination (i.e., anti-Vaxxers), and flat Earth beliefs – to illustrate how social media users exploit digital materiality and enact disinformation affordances. Our theoretical development also contributes to our understanding of how online disinformation disrupts institutional issue fields. In particular, we highlight several potential changes to institutional issue fields regarding power centralization, subfield structures, and institutional infrastructure. We conclude by offering recommendations for future research and social media policy.

通过社交媒体传播虚假信息已成为商界领袖和政策制定者紧迫的社会问题。近年来，网络虚假信息被认为是各种社会背景下实地制度变革的根源。为了更好地了解在线虚假信息如何改变机构问题领域，我们探讨了数字重要性如何为用户提供创建和传播虚假信息的机会。我们引入并定义了三个社交媒体材料特征：模块化内容、内容流和多样化的网络结构。从这些数字物质元素中，我们阐明了三种虚假信息的可供性：精心制作、放大和划分。我们依靠几个小插曲——极右政治阴谋团体、QAnon、反疫苗接种（即反 Vaxxers）和地平说信念——来说明社交媒体用户如何利用数字物质性并实施虚假信息可供性。我们的理论发展也有助于我们理解在线虚假信息如何扰乱制度问题领域。我们特别强调了有关权力集中、子领域结构和制度基础设施等制度问题领域的一些潜在变化。最后，我们为未来的研究和社交媒体政策提供建议。