This article presents the results of a public engagement experiment on a project trialling ‘vertical farming’, an emerging technology addressing urban food issues. The experiment developed within an issue mapping project, analysing debates about vertical farming on the digital platforms, Twitter and Instagram. The article presents a software tool designed to engage ‘offline’ publics in the issue mapping process, using images collected from Instagram. We describe testing this software tool with visitors to exhibitions of vertical farming in two science and technology museums. Our findings highlight the predominance of commercial publicity about vertical farming on Twitter and Instagram and the organisation of public attention around technological novelty. The article discusses the challenges such publicity dynamics pose to mapping issues on platforms. We suggest some ways digital methods might contribute to public engagement with technologies, like vertical farming, that are a focus of organised commercialised innovation.

本文介绍了一项针对“垂直农业”（一种解决城市食品问题的新兴技术）项目试验的公众参与实验结果。该实验是在一个问题映射项目中开发的，分析了数字平台、Twitter 和 Instagram 上关于垂直农业的辩论。这篇文章介绍了一种软件工具，旨在让“离线”公众参与问题映射过程，使用从 Instagram 收集的图像。我们描述了在两个科技博物馆与参观者一起测试这个软件工具的过程。我们的研究结果强调了 Twitter 和 Instagram 上垂直农业的商业宣传占主导地位，以及围绕技术新颖性组织公众关注。本文讨论了这种宣传动态对平台上映射问题的挑战。我们提出了一些数字方法可能有助于公众参与技术的方法，例如垂直农业，这是有组织的商业化创新的重点。