Ability grouping and subject acceleration could be used to tailor the curriculum to students' interests and learning speeds, but since those practices are not politically correct,

You know, we had a discussion a while ago about whether the tide is turning on this, and I have something to contribute on that. DD's K teacher has explained that during work time, there is color-coded (harder) work in math and reading boxes that he knows is for him. He also is in math and reading groups that meet with the teacher individually (I think his reading group has only two kids in it). When I expressed great gratitude for this--DD9 got no differentiation at all in K other than a few things we nagged for, like workbooks we brought in--she said "Oh, we all do it this way now. (DS) needs even more, but the grouping is standard." He also gets harder homework, which I think one other child also gets.