“互联网+”时代，在线教育打破了传统教育中的时空限制，成为了推动教育变革的重要形态。要想获得在线教育的高质量发展，就要正确认识其规律，尤其关注教与学的过程，而当前在线教育规律的研究集中在异步教学形式上，鲜少对直播教学中教与学过程进行深入探索。在疫情防控进入常态化的今天，在线直播教学以实时交互的优势已经广泛应用于各教育领域，在新的时空环境下，直播教学的特点和过程都发生了变化。因而正确认识直播教学规律，探索教与学过程中教师哪些“教的行为”能够对学生“学的行为”真正起到促进作用是提升教学质量的关键。

教学临场感通常用来了解在线学习环境中教师的教学情况，学习投入通常用来观测学生的学习过程和预测学习效果，所以研究利用“教学临场感”和“学习投入”来分别表征教的行为与学的行为。选取针对小学教师的在线直播培训课程作为研究对象，分别探索了直播教学中教学临场感的水平及特征、学习投入的水平及特征以及教学临场感与学习投入之间的关系。

首先，通过课堂观察法对教学临场感不同指标所对应的教学行为进行观测评分，发现在线直播教学临场感整体水平不高，尤其在学习的干预和评价方面较低。通过对比各节课的具体教学要素发现，高教学临场感的课程具有三个基本特征：内容实践性强并紧密结合教学实例；以学习者为中心组织丰富的课堂活动；通过多种互动方式促进理解。

其次，通过问卷法调研了直播课程中学习者的投入水平，发现整体的学习投入处于中等水平，尤其是行为投入中的“专注度”和“交互性”以及情感投入相对较低。同时通过差异分析发现，教龄较长的老教师学习投入水平普遍高于新手教师，英语和语文学科培训中学习者的情感投入和认知投入更高，数学学科则相对低一些。

最后，通过多元回归分析发现教学临场感对学习投入有显著的影响，其中学习的干预显著影响行为投入，学习的组织显著影响情感投入，学习的设计显著影响认知投入。同时，针对投入度最高的课程，以时间为单位对师生行为进行观察和编码，发现结合案例讲解的行为和教学交互行为（例如提问、讨论、情景模拟等）能够显著提升投入水平。

由此提出优化直播教学的建议，在学习的设计方面，要充分根据需求选择合适的教学内容，提升学习者的兴趣并激发学习动机。在学习的组织方面，要根据教学内容及重难点选择多样的教学方法，用好课堂提问、讨论、案例分析等方法，充分抓住学习者的注意力。在学习的干预方面，要重点关注教学交互，避免长时间的纯讲授，建立积极的学习氛围，在交流中促进知识建构。

In the era of "Internet+", online education, which breaks the time and space limitation of traditional education mode, has become an important form to promote educational reform. In order to develop the online education with high quality, it is necessary to explore the teaching rules, especially pay attention to the process of teaching and learning. The current research focuses on the asynchronous teaching form, and there is little in-depth exploration on the teaching and learning process in live teaching. Epidemic prevention and control has become normalized, and online live teaching has been widely used in various educational fields with the advantage of real-time interaction. Under the new space-time environment, the characteristics and process of online live teaching have changed. Therefore, the key to improving teaching quality is to correctly understand the rules of online live teaching and explore which "teaching behavior" of teachers can really promote students' "learning behavior".

"Teaching presence" is usually used to represent the teaching situation, and the "learning engagement" is usually used to observe the learning process of students and predict the learning effect. Therefore, the research uses "teaching presence" and "learning engagement" to characterize the teaching behavior and learning behavior respectively. Taking the online live training course for primary school teachers as the research object, this paper explores the level and characteristics of teaching presence and learning engagement, and the relationship between teaching presence and learning engagement.

Firstly, through the class observation method to score the teachers' teaching behavior corresponding to different indicators of teaching presence, it was found that the overall level of online live teaching presence was not high, especially in the aspect of learning intervention and evaluation. By comparing the specific teaching elements of each course, it was found that the course with high teaching presence had three basic characteristics: the content is practical and closely combined with teaching examples; organizing various class activities centered on learners; promoting understanding through multiple interactive approaches.

Secondly, through the questionnaire survey of learning engagement in the live course, it was found that the overall learning engagement was at a medium level, especially the level of emotional engagement and behavioral engagement of "concentration" and "interactivity". At the same time, through the difference analysis, it was found that the level of learning engagement was generally higher for veteran teachers with longer teaching experience than for novice teachers, the emotional and cognitive engagement of learners was higher in English and Chinese subjects than in mathematics.

Finally, through multiple regression analysis, it was found that teaching presence had a significant impact on learning engagement, in which learning intervention significantly affected behavioral engagement, learning organization significantly affected emotional engagement, and learning design significantly affects cognitive engagement. Meanwhile, for the courses with the highest level of engagement, teacher and student behaviors were observed and coded in terms of time, and it was found that the behaviors combined with case explanation and teaching interaction (such as questioning, discussion, scenario simulation, etc.) could significantly improve the level of engagement.

Thus, suggestions for optimizing online live teaching were proposed: in the design of learning, appropriate teaching contents should be selected according to the needs to enhance learners' interest and motivation. In the organization of learning, we should choose various teaching methods according to the teaching content, and use questions, discussions, case analysis and other methods to fully capture the attention of learners. In terms of learning intervention, we should focus on teaching interaction, avoid long-term pure lectures, establish an active learning atmosphere, and promote knowledge construction.