Over half a century has passed since Bruner suggested his three-stage enactive-iconic-symbolic model of instruction. In more recent research, predominantly in educational psychology, Bruner's model has been reformulated into the theory of instruction known as concreteness fading (CF). In a recent constructivist teaching experiment investigating two undergraduate students' combinatorial reasoning, we utilized an instructional approach that maintains the enactive-iconic-symbolic stages of CF, but through a gradual and much elaborated process. We found that our theory of levels of abstraction explicated the "fading" effect that is central to CF. In this theoretical report, we discuss how CF can be elaborated by our instructional approach and theoretical perspective. [For the complete proceedings, see ED630210.]