> This seems to be mostly false, in the sense that many schools run huge class sizes for many core courses (cough couch Berkely) and in practice non-TA instructionBerkeley is not a good counter-example.
There are usually several teaching professors doing a full time job behind the scenes -- handling a myriad of student crises, handling a huge quantity of special accommodations, plagiarism and other academic misconduct, behavior issues (on the part of both students and staff!!!), constant question bank maintenance, constant schedule tweaking, interfacing with faculty demands from down-stream courses, and so on. Those are all trivial, though. Most important -- by far -- is training and managing a large course staff most of whom have never taught a recitation or graded a homework assignment!
Scaling up from a class of 1 instructor and 40 students (at Olin 20 or 15 I'd guess?) in one class to class with 40 staff members and 1000+ students and several lecturers is its own skillset. Those instructors are not teachers. They are mid-level managers. It's a different job, and not one that most undergraduates are prepared to take on.
And the face that it's a machine matters. Teaching a few recitations or lab sections and grading homework is not even remotely the same as instructing a course.
It's a bit like saying that you don't need experienced management at a logistics company because, after all, everyone learns how to do the warehouse job within a week. True, but keeping that machine running requires institutional memory and is itself a full time job. And just because you can train cogs quickly doesn't mean many of those cogs would do a particularly good job at designing and operating the underlying machine. Or even a miniature version of that machine.
> but I think you might be underestimating how much better intentionally-designed support resources can make the process.
Having spent time both inside and outside the elite academic institutions, folks who use places like Olin or Berkeley as barometers for "normal" are wildly out of touch with 90+% of the 4,000 colleges and universities in the USA.
Students at places like Olin or Berkeley are already the cream of the cream of the crop. At Olin or Berkeley you have a handful of good student-educators every year. At normal places the acceptance rate is closer to Olin's reject rate, and the applicant pool is way lower quality. At normal places an above average Olin kid comes around once a decade or less, and the annual cream of the crop at Olin or Berkeley simply never pass through.