Intervention fidelity is an ongoing concern for rigorous research, from the initial stages of planning and study design to the maintenance of internal validity. An added concern is the balance between fidelity and design accommodation to better suit varied populations and individuals. In this article, we describe our process for monitoring intervention fidelity during an individualized, yet standardized, strengths-based intervention with homeless youths, in which we include periodic training of our professional intervention facilitators. In our ongoing study, which is based on a Solomon four-group design with repeated measures, monitoring and training are essential to ensure intervention fidelity. Despite a rich literature about intervention fidelity, little guidance is available to help researchers and practitioners implement fidelity strategies in the real world with vulnerable populations. This article addresses this gap.
Keywords: adolescence; community; location of care; methodological inquiry; methods; population focus.