The development of High-Performance Computing (HPC) programs is crucial to progress in many fields of scientific endeavor. We have run initial studies of the productivity of HPC developers and of techniques for improving that productivity, which have not previously been the subject of significant study. Because of key differences between development for HPC and for more conventional software engineering applications, this work has required the tailoring of experimental designs and protocols. A major contribution of our work is to begin to quantify the code development process in a specialized area that has previously not been extensively studied. Specifically, we present an analysis of the domain of High-Performance Computing for the aspects that would impact experimental design; show how those aspects are reflected in experimental design for this specific area; and demonstrate how we are using such experimental designs to build up a body of knowledge specific to the domain. Results t...