3MT (Three-minute thesis) presentations, in which students communicate their theses to non-specialist audiences within three minutes, have emerged as an important academic genre, echoing current practices in scientific communication where researchers report their research work to a heterogeneous audience. Although increasing attention has been paid to 3MT presentations, we still lack sufficient knowledge of how presenters should communicate disciplinary knowledge to a wide audience. To address this gap, this corpus-based study investigates the rhetorical organization of moves (i.e. discoursal units serving various coherent communicative functions in text) in 80 3MT presentations from six disciplines. It is found that orientation, rationale, purpose, methods and results are five obligatory moves, among which the results move comprises more than one-fifth of the total length. The rationale and results moves are more often applied in hard sciences than in soft knowledge fields. The findings shed light on advanced academic literacy and how students communicate disciplinary knowledge to a wide audience.

3MT（三分钟论文）演讲，学生在三分钟内将他们的论文传达给非专业观众，已经成为一种重要的学术类型，呼应了当前科学传播实践，研究人员向不同的观众报告他们的研究工作。尽管 3MT 演示越来越受到关注，但我们仍然缺乏足够的知识，了解演示者应该如何向广大观众传达学科知识。为了解决这一差距，这项基于语料库的研究调查了来自六个学科的 80 个 3MT 演示文稿中动作的修辞组织（即在文本中提供各种连贯的交际功能的话语单元）。发现方向、原理、目的、方法和结果是五个必须的动作，其中结果移动占总长度的五分之一以上。与软知识领域相比，基本原理和结果移动更常应用于硬科学领域。研究结果阐明了先进的学术素养以及学生如何向广大受众传播学科知识。