Gaps in content knowledge are easily filled if you make the effort. Gaps in skills may be a different matter, or maybe not.
Renzulli's compacting curriculum study in the early 1990s found that about half the curriculum could be eliminated for bright students without significantly impacting their achievement on tests designed for students a year older.
Students were selected for this study in a way that was not particularly scientific, and that's why I'm avoiding the label gifted here. Teachers basically just said, "I'll try it with this kid and that kid." Some of those had been formally identified as gifted, some of them were not.
