 When an instructor moves to online teaching, one of the first concepts encountered is that of the modes of teaching and learning. One mode is synchronous, examples of which are the virtual life classroom, live chat, video conference, instant messaging, webinar and so on. The other mode or approach is asynchronous, which includes examples such as pre-recorded video and screencast or slidecast uploaded on a learning management system. The LMS can also have features such as a discussion forum, quizzes and assignments, provision for collaboration, announcements, etc. At this point, the instructor has to make a choice, which mode to use. It's natural that we bring to this decision our experience teaching face-to-face classes. We may initially choose an approach based on this experience, that the synchronous approach is the option to go for because it seems to be the closest equivalent to the face-to-face class that we are so familiar with. So we may decide to do a virtual class over Zoom three times a week, similar to the face-to-face weekly schedule. We may include a few features from an LMS such as moodle homework at the end of a topic and email announcements. Pause and ask, is this effective? This model of three times a week Zoom classes plus some assignments. Let's pause and think about this question before proceeding. It turns out that the model just described does not constitute effective online learning. To understand why, we need to consider the situation from our students' perspective. Students may be facing access issues. For example, some of them do not have a smartphone. And even if they do have a smartphone or a laptop, the device might be shared between various members of their family and may not be available during the hours of the live virtual classroom. By definition, a live virtual class has a lack of flexibility in terms of scheduling. In addition, there may be issues of power or network which could cause disruptions in students accessing the live virtual class. Leaving aside the access issue, there is one more problem that depends on what actually happens during the live virtual class. It consists of an hour-long lecture and that too over a screen. We can only imagine what happens to student engagement let alone learning. In fact, we all know the challenges with student engagement even in physical face-to-face classes. Does this mean that one should never use Zoom or similar tools? Not at all. That is not the point being made. There are many excellent tools that support synchronous learning and other instructor needs. But the above problems are real and they do need to be addressed. The point is how do we exploit? The strategies and tools on the online medium to promote effective learning. These strategies and tools go beyond a live virtual classroom. The point, some of you may be thinking, what if in addition to three times a week live virtual classrooms, we record these sessions and upload the recordings of these sessions on the LMS? In addition, we will give homework at the end of the topic like earlier. It turns out that while this is useful, it is again not sufficient. Creating recordings of live classroom sessions and uploading them, they can definitely be useful, but they are not sufficient because there could be glitches in the recordings such as the voice breaking or the frames freezing. Even if we have the best quality software, maybe there were some bandwidth issues that led to some glitches. As instructors, we tend to not take these glitches very seriously. We think they're not so important in the grand scheme of things. But it's remarkable how easily and how quickly even minor glitches can demotivate students and lead them to lose attention in the meeting. Another reason why this is not sufficient is because lecture alone is not enough. Students need practice. They need activities for deeper engagement and lecture plus moodle homework at the end of a topic are not sufficient to provide such engagement. What's needed in addition are strategies which have been proven from decades of research in online education to be effective to promote student learning in this online medium. Let's look at two models which include such strategies and have been known to promote student engagement and learning. Model A, let's call this the one plus two model, is a mix of synchronous and asynchronous modes. Let's assume that the technologies in this course include Zoom for the virtual live classroom and moodle as the NMS. The synchronous mode comprises a virtual live classroom and live chat over Zoom implemented one hour per week. The emphasis of this course is in the asynchronous approach. This consists of pre-recorded videos within video quizzes corresponding to two hours of learning time per week. Learning time is the time it takes a student to go through the content, do the quizzes and assimilate the material. The videos could be talking head videos of the instructor or slidecast or screencast. The videos are followed by practice questions, no-stakes moodle quizzes based on the video proceeding it. The course also relies on discussion forums, discussion activities over a moodle forum. Model B, also known as blended online or flip class, primarily relies on the asynchronous approach. There are pre-recorded videos and screencasts within video quizzes. These are posted on a weekly basis and they correspond to about three hours of learning time per week. There are practice questions and no-stakes quizzes on moodle following each video and screencast so that students are able to practice and apply the material they learned in the video immediately. The course also consists of focused discussions based on a weekly topic which can be implemented over a moodle discussion forum. Frequent email announcements are sent out for scheduling, for updating progress, for encouraging students and this is done at a frequency of about two times per week or more. The synchronous component of this model consists of a live interaction usually over some video conferencing tools such as Google Hangout or Facebook Live. This interaction occurs three to four times per course which is roughly it could be once a month or once a fortnight. Why should we choose these configurations? Both these configurations as you saw consisted of a blend of the synchronous and asynchronous approach and they are designed to exploit the best of both approaches. They focus on flexibility as well as provide sufficient time to students for deep cognitive engagement with the materials since there is a greater emphasis on activities over the asynchronous mode. At the same time there is some component of a synchronous live interaction approach which lends itself to a personalization and immediate response. Model B has been implemented in several IIT Bombay X and NPTEL courses and we found from some data analysis and research that the live interaction that was implemented once a month improved the effectiveness of the course. At the same time the features of each course are designed to attempt to mitigate the limitations of each of the synchronous and asynchronous approaches. How should an instructor proceed now? We recommend that instructors choose one of these two models to map on to whichever works better with your course, learn the corresponding technologies and apply the related best practices so that one has a well-designed online course. Thank you.