Interleaved Pattern Composition and Scaffolded Learning

One of the essential skills required in the design of computer programs is the composition of design patterns in an interleaved way. We expect both beginners and senior students to demonstrate competence with this skill. Are they competent? Not quite. We found that both novices and seniors demonstrate disturbing difficulties with interleaved pattern composition. In order to address these difficulties, we developed a scaffolding instruction approach, which we applied with students. We display our findings, our approach, and the approach implementation.