This handbook presents a methodology that seeks to address a knowledge gap. Termed the Assessing Integration Methodology, or AIM, it has been developed from experience gained by the Population Council in undertaking assessments of various combinations of integrated services in many developing countries, most of which was undertaken through the USAID-funded Frontiers in integrated services. The handbook (a) explains the basic principles of conducting studies using AIM, (b) provides tips for the data collection, and (c) makes available data collection instruments that have been validated in projects throughout the developing world. The map on the previous page highlights those countries in which FRONTIERS carried out projects utilizing the AIM strategy.