How do infants come to learn about and understand the large numbers of objects, events, and people they encounter? It is remarkable that by one year of age, the typical infant in middle-class American culture knows that dogs say "woof," you drink from cups, and there is a class of round objects called "balls." Science has focused both on how infants come to represent the properties of particular objects (e.g., my teddy has a red shirt) and classes of objects (e.g., cars have wheels). The functions of objects are central to many concepts -- we learn not only the surface features of objects (such as shape and color), but also about how objects can be used and for what purpose they were created (e.g., to hold liquid, to make marks on paper). Despite the large literature documenting infants' impressive abilities to acquire knowledge about objects, and the importance of function to how objects are represented, we know little about infants' emerging abilities to represent function. This work will address this gap by examining infants' emerging understanding of function from 6 to 12 months, and by determining how their developing abilities to manually explore objects (i.e., pick them up, rotate them) is related to their understanding of function. By measuring aspects of infants' looking behavior -- how long they watch particular events, where they look -- we can understand how they learn about and represent the objects and actions in these events. By observing how they play with objects -- how easily they pick them up from the floor, how long they inspect objects in their hands -- we can measure developmental changes in infants' abilities to manually explore objects. In this work, both looking at images and playing with objects will be assessed in infants to document how developments in the two areas are related. Filling this gap in our knowledge is important because of the significance of function for understanding object representations in general and because understanding typical development of object representation is critically important for a full appreciation of atypical developmental patterns of object representation, such as those associated with Williams Syndrome and autism spectrum disorder. Individuals with these disorders often have difficulty learning about and representing objects and actions, particularly the actions performed by humans on objects. Unfortunately, these disorders are often not identified until later in childhood, and as a result we know little about the early emergence of these atypical patterns of development. A comprehensive understanding of the typical development of object representation in infancy may aid in early identification and treatment of individuals with such neurodevelopmental disorders. A full understanding of typical development of basic cognitive abilities, such as infants' representation of objects, is also important for educating parents and caregivers about development and appropriate expectations for infants. The results of this work will be broadly disseminated, not only to the scientific community through publication in scientific journals and presentation at national and international conferences, but also to parents and childcare professionals through lectures given to parenting groups, participation at the Yolo County Child Development Conference, and television and radio.