So here's my rough sketch of a tech-facilitated delevelled high school science classroom:
I envision a single chemistry course (not counting AP) offered for students regardless of previous "level" or readiness.
The basic structure is a menu of activities, projects, online videos, readings, and formative assessments in each unit, ranging from a basic to advanced level. For example, the atomic structure unit could include videos/readings on protons, neutrons and electrons on up to solving for the masses of isotopes and writing balanced equations for fission reactions. Students could progress through the material at their own pace, skipping sub-units if they already knew the material.
Performance tasks and adaptive online assessments would measure their level of mastery of each unit, with student performance rated on a 5 point scale something like this:
1. Developing (student has not yet mastered basic practical chemistry concepts)
2. Basic (student has mastered basic practical chemistry concepts)
3. Proficiency (student has mastered college prep-level chemistry content)
4. Mastery (student has mastered advanced college prep-level chemistry content)
5. Expertise (student has achieved extraordinary mastery at the advanced level))
I envision one classroom with this full range of students, all working on this menu of activities, projects, and online resources in small groups or individually, with guidance, help, assessment, and direct instruction from the teacher, as necessary. They could work at their own pace, but a schedule of units for the year would be provided to act as a pacing guide.