# A Review of Multimodal Interaction in Remote Education: Technologies, Applications, and Challenges
## 1 Introduction  
The word \"multimodal\" defines the blending of more than one human sense modality, which includes vision, touch, hearing, and taste and smell, as well as communication skills like perception, cognition, and interaction. The main purpose of multimodal interaction is to help users better understand the information presented by computing systems [1]. This is usually achieved by technologies that are based on user senses, such as haptic devices, virtual reality (VR) systems, and augmented reality (AR) systems. In systems of multimodal interaction, users can participate in interactions that are either uni-directional or bi-directional, which makes it easier to monitor and study user activities [2]. This technology is considered important for interactions with computers at the virtual level. As an example, [PERSON] et al. [2] studied verbal and non-verbal user behaviors, while engaging with virtual agents and supplemented emotion recognition through electroencephalography (EEG) and electrodermal activity (EDA) to improve the experience for users. Furthermore, some researchers have reported that visual and dynamic feedback [3] can enhance user engagement in virtual places more easily [4]. [PERSON] et al. [4] showed how virtual environments can be enhanced by optimizing visual feedback for virtual reality environments to improve instruction for skilled digital human-computer models, while exploiting the models for improved instructional outcomes of grasping actions. Dynamic feedback systems are an essential feature of multimodal interaction. For instance, [PERSON] et al. [3] designed a system that allows users to give virtual speeches to an audience that can provide feedback as the user speaks through voices, gestures, and even facial expressions. This improves the skill of public speaking among users. In the same vein, [PERSON] et al. [5] investigated haptic interaction on a virtual agent, enabling two-way communications by proving that virtual agents not only act on the user's actions, but also communicate through haptic response, thereby increasing user engagement. The main goal of multimodal interaction is to make human-computer communication more natural, allowing systems to better understand users' intentions and emotions [6]. This technology is used not only in AR and VR but also in remote education, where it helps improve learning experiences and results. In recent years, the fast development of AI, computer vision, and sensors has led to the wide use of multimodal interaction in education. By combining speech, gestures, and facial expressions, multimodal feedback can effectively increase learners' engagement and understanding. Traditional learning analytics mainly use single data sources, such as clickstreams, log records, and interaction data from learning management systems (LMS). These sources show only part of the learning process and do not provide a full understanding [7]. Learning is also shaped by hidden factors, such as cognitive states and emotional changes, which strongly affect learning outcomes [8]. Standard data collection methods often miss these behavioral, attentional, and emotional shifts. Multimodal data analysis can help address this gap. Studies show that traditional learning analytics rely on limited data, like click data and system logs, which do not fully capture learning activities [9]. Multimodal learning analytics, however, combines different data types, such as EEG, EDA, facial expressions, and speech signals. This approach provides a clearer picture of learners' cognitive and emotional states, making personalized learning more effective [10]. Multimodal interaction technology offers a way to overcome the limits of traditional learning analytics. It makes remote education more flexible and engaging while giving learners real-time, personalized feedback. As AI, computer vision, and sensor technologies improve, multimodal interaction will play a larger role in education, offering new ways to personalize learning and assess students.