This study proposes affordances for discursive opportunities (ADO) as a theoretical framework that leverages the concept of technological affordances and the theory of discursive opportunities to understand platform potential in shaping social media activism. Specifically, ADO underscores how social media platform affordances (e.g., algorithmic curation, shared group identity and culture, connectivity) shape movement visibility, resonance, and legitimacy, all of which can mobilize activism efforts. We further situate our discussion in the cross-platform context to explore both differences and interconnections between different platforms in facilitating digital activism. By analyzing 20,363,128 English posts related to the #MeToo movement from 2017 to 2020 on Twitter, Facebook, and Reddit using supervised machine learning and time series analysis, we reveal platform variations in affording discursive opportunities for visibility, resonance, and legitimacy, which shape activism efforts differently across platforms. We also find a unidirectional relationship from activism on Twitter and Reddit to activism on Facebook.

中文翻译：

---

平台可供性、话语机会和社交媒体激进主义：2017-2020 年 Twitter、Facebook 和 Reddit 上 #MeToo 的跨平台分析


本研究提出了话语机会的可供性 （ADO） 作为一个理论框架，它利用技术可供性的概念和话语机会理论来理解平台在塑造社交媒体激进主义方面的潜力。具体来说，ADO 强调了社交媒体平台的可供性（例如，算法管理、共享群体身份和文化、连接性）如何塑造运动的可见性、共鸣和合法性，所有这些都可以动员激进主义的努力。我们进一步将我们的讨论置于跨平台背景下，以探索不同平台之间的差异和相互联系，以促进数字行动主义。通过使用监督机器学习和时间序列分析分析 2017 年至 2020 年在 Twitter、Facebook 和 Reddit 上与 #MeToo 运动相关的 20,363,128 篇英文帖子，我们揭示了平台在提供可见性、共鸣和合法性的话语机会方面的变化，这些机会在不同平台上以不同的方式塑造了激进主义工作。我们还发现，从 Twitter 和 Reddit 上的激进主义到 Facebook 上的激进主义，存在着单向的关系。