• evidence-based practice;
  • health services research;
  • homelessness;
  • program evaluation;
  • program logic analysis

ABSTRACT Maintaining the alignment between the dynamic development of health and social services and the rapidly advancing scientific evaluation literature is a central challenge facing service administrators. We describe “program explication,” a consulting method designed to assist services to identify and review implicit program logic assumptions against the evaluation literature. Program explication initially facilitates agency staff to identify and document service components and activities considered critical for improving client outcomes. Program assumptions regarding the relationship between service activities and client outcomes are then examined against available scientific evidence. We demonstrate the application of this method using an example of its use in reviewing a service for homeless young people operating in Melbourne, Australia, known as the Young People's Health Service (YPHS). The YPHS involved 21 activities organized within 4 components. The intended benefits of each of the activities were coherently articulated and logically consistent. Our literature search revealed moderate to strong evidence for around 1 quarter of the activities. The program explication method proved feasible for describing and appraising the YPHS service assumptions, thereby enhancing service evaluability.