Functional Design V

Functional design supports the simultaneous consideration of parallel alternatives—design hypotheses—and reduces the sequentiality of decisions. It encourages the evaluation of clusters of decisions which must work together to create design unity. It enables designers to hold off firm decisions on a cluster until the impact of the decisions on cost, skill, time, and tools has been determined. A functional designer will most likely advance the design within many layers at once through interdependent decisions spread across multiple layers. The method of proposing hypothetical designs and testing them is described by Schön as a design “conversation”. Just as Schön’s domains of an architectural design define the loci of individual design decisions, the layers and sub-layers of an instructional design localize the attention of the instructional designer without obscuring the integrity of the whole.