Contents I. INTRODUCTION
With the help of computer-mediated communication, learners can effectively connect with other learners, participate in rich and real knowledge construction activities, and effectively create learning communities and reap learning results. When knowledge construction is used as a method of schooling, the goal of students is to learn by participating in this collaborative, critical dialogue of ideas, so knowledge Forum software is a good example of creating a knowledge-based learning community. As the basis for knowledge construction of Online learning communities, Online Asynchronous Discussions (OADs) take place through participants asking questions, sharing ideas, and providing feedback (DeWert, Babinski, and Jones, 2003), Achieve text-based computer-aided communication without space-time constraints (Hew, Cheung, and Ng, 2010, p. 572). Online asynchronous debates highlight student-centred learning activities (Trinidad and Ngo, 2019). It has three main advantages: supporting learning anytime and anywhere (Wirtz et al., 2018), personalized learning (Thomas, 2013) and providing learners with sufficient time for thinking (Putman, Ford, and Tancock, 2012). Learners through online activation link knowledge and construct cognitive network, provide a temperature collaboration and competition of the emotional experience, enrich the learning process and further promote the multi-dimensional targets agreed upon, to give participants the feeling of competence of flexible use of knowledge, “turn knowledge into wisdom” in education field to better highlight by course education connotation of learning process, however, there's a lack of attention to online asynchronous discussion evaluation, and the existing literature mainly focuses on the creation of online asynchronous discussion environment (Liu Sannyeya, Hu Tianhui, and Chai Huanyou, 2021) and strategies for improving learners' status (Wang Zhiying, Zhai Yun, and Wu Juan, 2021). In order to give full play to the role of online asynchronous discussion, it is essential to grasp its function and influence effect. Consequently, this survey focuses on the multidimensional evaluation of online asynchronous discussion of blended learners. In the new century, the transformation of learning methods, assessment methods and teaching methods, as well as the upgrading of infrastructure and the reconstruction of the education system can better prepare learners for the future. According to relevant studies, an active, mixed and collaborative learning environment can improve students' knowledge construction ability and problem solving ability (Rhoads, Nauman, Holloway and Krousgrill, 2014).In 2003, the American Society for Training and Development identified blended learning as one of the top ten trends to emerge in the knowledge delivery industry (cited by Rooney, 2003). According to NETP2016, the goal of learning is to enable all learners to acquire learning experiences through immersive and autonomous learning in formal and informal settings, and focus should be placed on cultivating students' 21st century abilities and professional knowledge. Including critical thinking, complex problem solving, collaboration and multimedia communication skills, and the development of these skills into traditional subject teaching.
