Should remote teaching sessions be shorter than classroom sessions?
If you search using Google or another search engine for something like &quot;research on maximum effective lecture time&quot; you will get some ideas. In general, long lectures are less effective than short ones because of the student's attention span. Video lectures should be very short, say 10-15 minutes for effectiveness. And with required activities at the end of each short session. So, a long &quot;lecture&quot; can be presented as a sequence of short but complete segments. Real time is a bit different, but keep all of that in mind in course design.
But it really depends on what you and the students are doing in the given time period, rather than the length itself in any absolute sense. A talking head writing on a board or (worse) showing a bunch of slides gets old and boring very fast. If the students have a chance to break it up with questions or some problem solving activities it is better and the class-period can be longer and still effective. Class discussion sessions is another way to break the monotony, but harder online and nearly impossible with video unless there is an effective communication channel shared by every student.
I used to teach a couple of courses that lasted all day and only met once a month. But the face time was usually broken up into small segments and we used very effective, but simple, communication tools so that students could &quot;engage&quot; with the course and the instructors (two of us) at any time through the period between face-time sessions.
The key is to keep the students active and engaged. Once they lapse into passivity you are lost. Some students have the skills and background to keep themselves engaged in sub-optimal environments, but not all do. Perhaps not even the majority.