Whould the approach to primary school-level home education differ from high school-level?

Yes. During the primary years homeschoolers not only concentrate on teaching numeracy and literacy but most importantly on developing a love for learning and good books by reading aloud a lot to everyone. The child's natural inquisitiveness is not suppressed but encouraged and regular excursions into the big wide wonderful outdoors is a regular occurrence. During high school however learning often becomes a little more structured with the young adult taking more responsibility for his learning and the parent becoming a sounding board and mentor.