Central Concept Unit This is a three week, concept-based unit in which I provide instruction two to three days per week in partnership with teachers. This is a unit which we have co-designed and one which we will co-teach including delivery of the homework assignments. One central concept is pursued in-depth encouraging divergent explorations around related themes and student passions. This unit is a good opportunity to explore constructivist instructional strategies. Handy also is the rubric I've designed for "How To Do Good Research."