This chapter reviews the various methods that researchers have used to study infant cognition from birth through 2 years of age. Most of these methods can also be adapted to the study of infant perception. The authors have emphasized research methods that have been applied to classic experimental problems, including habituation, classical and operant conditioning, detour learning, concept formation, categorization, spatial learning, serial‐list learning, and memory processing. Some of the well‐developed methods that have been applied to a particularly wide range of problems are highlighted. In the learning section, for example, the authors have detailed the basic features of habituation and conditioning phenomena; later in the chapter, they describe how habituation and conditioning procedures have been used as tools to study other cognitive phenomena in infants. The chapter also includes descriptions of some of the methods that have been developed to study special problems in early cognition, such as infants' object representations (individuation, segmentation), their understanding of number and causality, and their attentional processes in visual search tasks. Finally, the chapter considers problems commonly encountered in infant research as well as some of the practices that can lead to ambiguous results and erroneous conclusions.