A crucial challenge for the coordination of horizontal policy programs-those designed to tackle crosscutting issues-is how to motivate government organizations to contribute to such programs. Hence, it is crucial to study how practitioners in implementing organizations view and appreciate the coordination of such programs. Assisted by Q-methodology, this inductive study reveals three significantly different "images": central frame setting, networking via boundary spanners, and coordination beyond window dressing. Most surprisingly, different images show up among respondents within the same organizations and horizontal programs. The authors find that the images reflect elements of the literature: the resistance to hierarchical central control, the need for local differentiation and increased incentives, and a collaboration-oriented culture. Most importantly, practitioners of implementing organizations perceive top-down mechanisms as ineffective to achieve coordination and ask for adaptive arrangements, involvement, and deliberative processes when designing coordination arrangements and during the collaboration.
Evidence for Practice• Coordination arrangements for horizontal policy programs that are purely hierarchical are seen as undesirable by practitioners in implementing organizations and can have unintended effects on implementing organizations. • As top-down mechanisms are insufficient on their own to create collaboration, involving the implementing organizations in the design of the coordination arrangement is important. Implementing organizations prefer that the center of government thinks in tailor-made terms, takes into account varying images of coordination, and invests in the participation of organizations, which in the end have to implement the tasks. • Some practitioners prefer boundaries with room to maneuver at the organizational level, others believe in collective action, and some are disheartened by earlier government-wide approaches and want to see real action before they are willing to commit. Therefore, choosing a hybrid coordination approach, combining cultural and instrumental aspects such as incentives, and sequencing different coordination approaches appear to be good strategies. • This study supports the call for adaptive and reflexive coordination arrangements, in which coordinators keep an eye on both the macro-dynamics of the coordination arrangement over time and the alignment of individual organizations that need to implement the horizontal policy programs.