A Theoretical and Empirical Comparison of Two Mixed-Factor Central-Composite Designs.

This paper provides a brief review of the application of central-composite designs CCD in human performance research. Particular mention is made of the mixed-factor CCD, which allows simultaneous consideration of within-subject and between-subjects factors. The current paper details the construction of two alternative versions of such a design. After the two versions have been compared on theoretical grounds, an empirical investigation is proposed to determine the relative predictive accuracy and validity of prediction equations derived from data collected in accordance with each design version.