When presenting to a large group of students, either in an amphitheatre or through an online platform, effectively connecting to the audience – understanding how well the audience is following the presentation and taking appropriate actions promptly if they experience difficulties – is a serious challenge. Backchannel systems are sometimes deployed to address this issue by allowing audience to give feedback to the presenter without interrupting the current discourse. However, these systems are not designed to immediately aggregate and present the audience's feedback to the presenter in a meaningful way that is easy to quickly digest. To fill this gap, we have explored a proof-of-concept method for analysing the emotions and sentiments from the audience's feedback in real time and displaying to the presenter a morale graph showing a trend of the audience's overall reaction over time. This allows a presenter to effectively connected to their audience in real time, knowing whether their presentation is going well and what issues their audience may have in common at any specific moment. We have further implemented this method in an educational context, using a prototype backchannel system, known as ClasSense, for a lecturer to effectively connect to their students. This paper presents the evaluation of this system, which shows that lecturers accept and prefer the morale graph based user interface developed over other backchannel user interfaces that display all posts in chronological order. Students also positively expressed their agreement that the system not only makes their feedback an important part of the class but also increases their interactions with the lecturers. This is further confirmed with a Markov chain predicting the probability that students’ and lecturers’ survey results lead to their overall positive sentiment towards the tool. The flexibility of the ClasSense system suggests it may also be suitable in contexts other than education.

在圆形剧场或通过在线平台向一大批学生进行演讲时，有效地与观众建立联系-了解观众对演讲的了解程度，并在遇到困难时迅速采取适当的行动-是一个严峻的挑战。有时会部署反向通道系统来解决此问题，方法是允许听众在不中断当前演讲的情况下向演示者提供反馈。但是，这些系统并非旨在立即聚合并以易于快速消化的有意义的方式向演示者呈现观众的反馈。为了填补这一空白，我们探索了一种概念验证的方法来分析观众的情感和情感。实时反馈，并向演示者显示一个士气图表，该图表显示了随着时间的推移，观众的总体反应趋势。这使演示者可以实时有效地与他们的听众建立联系，知道他们的演示进行得是否顺利，以及听众在任何特定时刻可能有哪些共同点。我们使用一种称为Backchannel的原型系统在教育环境中进一步实现了此方法ClasSense，让讲师有效地与学生联系。本文介绍了该系统的评估，表明与其他按时间顺序显示所有帖子的反向用户界面相比，讲师接受并偏爱基于士气图的用户界面。学生们也积极表示同意，该系统不仅使他们的反馈成为班级的重要组成部分，而且增加了与讲师的互动。马尔可夫链进一步证实了这一点，该链预测了学生和讲师的调查结果导致他们对该工具产生总体积极情绪的可能性。ClasSense系统的灵活性表明它也可能适用于教育以外的环境。