Last semester, I was teaching a class where there is a small assignment (~2% of the total course assessment) that students need to submit every week. Unfortunately, some of the students joined the class late, due to add/drop forms that needed to be signed manually, or for other unknown reasons.
Is it fair to give zeros to students who missed early assignments because they added the class late? There were a few students who may have missed 3 or 4 weeks of assignments.
Response to comment
Q: Were the students not able to physically be present? Were the students not able to predict that they would take your class?
They were physically able to be present. Some students may not have been able to predict that they were able to take my class. For example, one student had to add the class after the add date deadline, because he was admitted late to the university.
After thinking things through, I checked that the last date for adding the course is the Monday of week 2, and the first weekly assignment is also assigned and due in week 2. I found in the data that there were several students who did not attend in week 1, but all of these students attended and submitted the weekly assignment in week 2.
Consequently, all of the students in the course were registered by week 2, and would have been able to submit all the weekly assignments. Thus any students who did not submit a weekly assignment deserve to get zero for that assignment, unless they have a reason to be excused.