This is one issue that I'm passionate about. Research increasingly implies that homework is probably harmful in elementary; of dubious value in early middle school; and only valuable in high school and beyond.
> and objective performance assessments
I think some of these radical experiments are crazy. But, there's valid reasons to consider e.g. not grading missing absent assignments as a zero. A few of them:
A) If our goal is for grades to reflect demonstrated student mastery --- a missing assignment doesn't indicate that proportion of mastery "missing." Especially if it has been demonstrated satisfactorily on an exam or by other measures.
B) A couple zeroes on a gradebook can be an insurmountable hill to climb-- leaving no further grade incentive at all for students to work hard in the class.
C) Grades are strong motivation for already-strong students with the most involved parents, but can actually be demotivating for the bulk of your class. An effective teacher needs to find other ways to motivate students. For many students, grades are something that can make one feel bad about oneself but not provide an opportunity for positive differentiation.
The classes I teach are "easy A's" in the gradebook for most of my students... and are incredibly demanding compared to normal MS/HS fare. This requires buy-in from my students. I work to build genuine curiosity and in-class competition (on a variety of axes where all students can excel, not just the top couple dunking on everyone else).
Grades themselves are truly a mixed bag. They typically conflate work submitted with material learnt, communications skills, work ethic and motivation, as well as any other factors that implicitly seep into the approach the teacher employs (e.g. communicating expectations and meaningful feedback). Grades really should be abolished for more descriptive assessments, unfortunately almost everyone from students to families to schools to boards of education to ministries of education wants quantifiable metrics.
I learned the hard way that skipping the homework means bombing the test. You don't learn problem solving skills by listening to a lecture or watching TV. It's easy to imagine you've learned it, till you're confronted by the test.
I remember my highschool chem teacher harping on the class after every test "I'd like to tell you all that if you don't do the homework, you won't pass the test, but toast0 didn't do the homework and did the best on the test so do the work" (or something like that). To be fair, I'd look at the homework, I just didn't feel like writing it down and turning it in, most of the time, so for classes where grading let me skip homework and I felt I had a good grasp of the material, I skipped it.
But, for kids like me, we'll succeed im school as long as there aren't active roadblocks from staff (or other students or other life issues). I think the real question is how to help the kids that need help. How do we get them motivated and engaged and empowered to learn the material?