Digital media have become central to how labor unions communicate, organize, and sustain collective action. Yet little is known about how unions' online discourse relates to concrete outcomes such as representation elections. This study addresses the gap by combining National Labor Relations Board (NLRB) election data with 158k Facebook posts published by U.S. labor unions between 2015 and 2024. We focused on five discourse frames widely recognized in labor and social movement communication research: diagnostic (identifying problems), prognostic (proposing solutions), motivational (mobilizing action), community (emphasizing solidarity), and engagement (promoting interaction). Using a fine-tuned RoBERTa classifier, we systematically annotated unions' posts and analyzed patterns of frame usage around election events. Our findings showed that diagnostic and community frames dominated union communication overall, but that frame usage varied substantially across organizations. In election cases that unions won, communication leading up to the vote showed an increased use of diagnostic, prognostic, and community frames, followed by a reduction in prognostic and motivational framing after the event--patterns consistent with strategic preparation. By contrast, in lost election cases unions showed little adjustment in their communication, suggesting an absence of tailored communication strategies. By examining variation in message-level framing, the study highlights how communication strategies adapt to organizational contexts, contributing open tools and data and complementing prior research in understanding digital communication of unions and social movements.

翻译：数字媒体已成为工会沟通、组织和维持集体行动的核心平台。然而，关于工会线上话语如何与代表权选举等具体结果相关联，目前知之甚少。本研究通过整合美国国家劳工关系委员会（NLRB）选举数据与2015年至2024年间美国工会发布的15.8万条Facebook帖子，填补了这一研究空白。我们聚焦于劳工与社会运动传播研究中广泛认可的五个话语框架：诊断性（识别问题）、预测性（提出解决方案）、激励性（动员行动）、社群性（强调团结）和参与性（促进互动）。通过使用微调的RoBERTa分类器，我们系统标注了工会帖子，并分析了选举事件前后框架使用的模式。研究发现：诊断性与社群性框架在工会整体沟通中占主导地位，但不同组织间的框架使用存在显著差异。在工会获胜的选举案例中，投票前的沟通显示出诊断性、预测性和社群性框架使用的增加，而事件后预测性与激励性框架使用减少——这种模式与战略筹备相一致。相比之下，在失败的选举案例中，工会的沟通策略几乎未作调整，表明其缺乏针对性沟通策略。通过检视信息层面框架的差异性，本研究揭示了沟通策略如何适应组织情境，贡献了开源工具与数据，并补充了先前关于工会与社会运动数字传播的研究。