I asked a question, a number of people answered, and I disappeared. The answers all now say "11 days ago". My belated thanks. Essentially I was asking about this idea of "many hours / lots of repetitions".
@Ithaca wrote "KS, as a child I wasn't told to do "lots of repetitions", but my teachers told me to practice at least an hour/day once I turned 8. .... During that time my 2nd teacher gave me brief instructions on what to practice, but not very much about how, since it was clear I wasn't putting in the time. Once I started playing regularly most days, she started giving me her thoughts on how to practice; e.g., what order to do things in, number of repetitions (but not very many, IIRC), etc."
@twocats wrote "I don't think the 2.5 hour expectation was from my teacher but from my dad; we were in Canada but had a strict and scary Russian teacher. I don't remember if she had suggested a certain number of hours of practice,....
But I do remember long hours and lots of repetition was the expectation. No one has ever told me to do small segments and to break it up."
What I'm getting in general is that stated or implied, an expectation of longer hours were understood, but not much by way of what do do during those long hours.
In my first-ever lessons which were on violin, I was told that good students tended to practise daily from 1-3 hours, but the "how" of that practice likewise was never taught. I started questioning that aspect of it several years in when things both hit a ceiling and also had gone backward.
Ithaca, the observation by the specialist about the conservatory students was both interesting and disturbing.
@ranjit - You were told to try 6 hours for the level you are trying to reach, but also the "high level of focus" part. The "high level of focus" brings us right back to "how to practise" - how do we spend the time we're at the piano (or away from it if mental practice is included), and how do we divide up our time.
That is my poor summary. I hope I haven't left anyone out. I thank everyone for your input to my question.