@JBStillFlying
If the current system is anything like last year’s, this should be the case. Although…
This is a new addition to the portal, so the system’s changed at least a little. Last year, everyone walked into an adviser’s office with their #1, #2, #3 sections (HUM and SOSC) and other classes of interest written on a sheet of paper. Advisers then checked the class registration portal to see if those sections/classes had space, placed students in various sections and classes manually, and sent us on our way. To prevent students whose adviser meetings were at the start of O-Week from getting priority over others, SOSC/HUM sections were gradually opened as the week progressed.
This wouldn’t work before students arrive on campus, obviously. The only reason pre-registration during the summer is possible now is because the portal has been revamped for first-years. On the flip side, all sections are being opened at once, since pre-registration occurs “simultaneously.”
I agree that listing SOSC before math is the optimal ranking (see above) but I wouldn’t read too much into the fact sections are half-full. The registrar’s office aims for a balance of first-years and second-years in every SOSC section (though this balance will shift a little as a result of add/drop decisions in September). This means 9-10 spots are usually filled by second-years during pre-registration at the end of Spring Quarter, and then first-years get their shot at the remaining 9-10 places.
There may be some tweaking going on - you’d have to ask College Advising to know for sure. If there’s a survey out there asking about context, it seems likely.
The tweaking isn’t likely to begin for a week or two, though. During the academic year, pre-registration takes place during 8th week of each quarter and schedules are posted sometime during 10th week. The system takes a while.
A word of warning: if a partial schedule suddenly pops up on your D’s My.uchicago page, then disappears or changes, don’t read too much into it. The algorithm will sometimes do its work in plain view - and the process is fairly messy. Schedules, final or otherwise, were posted earlier than planned during the last two rounds of pre-registration.