Effective independent civil society monitoring of public policy processes requires "vertical integration" to monitor different elite actors simultaneously. Vertical integration refers here to the coordination of policy monitoring and public interest advocacy efforts across different "levels" of the policy process,from the local to the national and transnational arenas. Systematic, coordinated monitoring of the performance of all levels of public decision making can reveal more clearly where the main problems are, permitting more precisely targeted civil society advocacy strategies. Because policy makers' information about actual institutional performance is very limited, rarely field based, and drawn mainly from interested parties (especially in the case of large-scale, decentralized social programs), the resulting information gap creates opportunities for advocacy groups to use independent monitoring to gain credibility and leverage. This article, written originally for a Mexican activist audience, explores the implications of this approach in the context of civil society efforts to monitor and influence World Bank projects.