This guide is intended to assist researchers, who are already familiar with formative research methods, in conducting formative assessments for infant and young child feeding programs. It offers a brief orientation to infant and young child feeding; describes major formative research methods and techniques that can be applied to nutrition; outlines a process for determining the appropriate formative research approach; and provides guidance for analyzing the information collected. The document also includes examples of formative research tools and plans and offers suggestions for analytical tools and formats.