As policy emerges from the interplay of economic, political, and socia
l forces, determining whether research has made a difference to policy
choices on aging issues is extremely difficult. Such a determination
demands attention to the ''black box'' of the policy process, and the
setting within which policy ultimately operates. This paper presents a
Seniors' Independence Research Program as a case illustration of how
research has made a difference to policy choices by stakeholder involv
ement throughout the research process. Strategies ensure stakeholder c
ollaboration in policy issue search, filtration, definition, and prior
itization; involvement in the design, implementation, and evaluation o
f health services models; and participation in achieving long-term evi
dence-based changes in policy and practice.