This study explores teacher educators’ (TEs’) activity as they support mathematics and science teacher collaboration in co-designing and jointly implementing tasks. We view TEs’ activity through the lens of Activity Theory and expansive learning and draw evidence from data generated within the mascil project that linked mathematics and science teaching with workplace situations through inquiry-based teaching. We focus on five TEs’ actions and goals, use data from their professional development sessions with teachers and from the TEs’ interactions during their own meetings, and highlight the illuminating case of one teacher educator. We trace evidence indicating paths of actions followed by each Teacher Educator and look for indications of their professional learning. Our analysis reveals generic and content-focused actions. All TEs faced different kinds of contradictions and had difficulties handling them. In terms of professional learning, all TEs adapted their prior teacher education practices and appreciated the critical role of epistemological differences between the two disciplines.

这项研究探讨了教师教育者（TEs）的活动，因为他们在共同设计和共同执行任务时支持数学和科学教师的合作。我们通过活动理论和广泛学习的视角来查看TE的活动，并从mascil项目中生成的数据中汲取证据，该项目通过基于探究的教学将数学和科学教学与工作场所情况联系起来。我们专注于五个TE的行动和目标，使用他们与老师的专业发展会议中的数据以及TE在他们自己的会议中的互动，并重点介绍一位教师教育者的启发性案例。我们追踪证据表明每位教师教育者应采取的行动路径，并寻找其专业学习的迹象。我们的分析揭示了通用的和以内容为中心的动作。所有TE都面临着各种各样的矛盾，并且很难处理它们。在专业学习方面，所有TE都适应了以前的师范教育实践，并赞赏这两个学科之间认识论差异的关键作用。