PROBING THE EFFECTS OF INDIVIDUAL COMPONENTS IN MULTIPLE COMPONENT PREVENTION PROGRAMS

Assessing the contributions of individual components in multi-componen t interventions poses complex challenges for prevention researchers. W e review the strengths and weaknesses of designs and analyses that may be useful in answering three questions: (1) Is each of the individual components contributing to the outcome? (2) Is the program optimal? a nd (3), Through what processes are the components of the program achie ving their effects? Factorial and fractional factorial designs in whic h a systematically selected portion of all possible treatment combinat ions is implemented are used to address question 1. Response surface d esigns in which each component is quantitatively scaled are explored i n relation to question 2. Mediational analysis, a hybrid of experiment al and correlational approaches, is considered in relation to question 3. Design enhancements are offered that may further strengthen some o f these techniques. These techniques offer promise of enhancing both t he basic science and applied science contributions of prevention resea rch.