Visual attention is thought to be influenced by two categories of factors, those thatare top-down and endogenous (e.g., prior knowledge, current goals, etc.) and those that are bottom-up and exogenous (e.g., properties of external stimuli such as color, contrast, and orientation). The primary aim of the three studies included in this dissertation is to assess how particular types of top-down information (underlying environmental regularities and prior knowledge) influence attention across development (Chapter 2) and in conjunction with motor factors (Chapters 3 and 4). Chapter 2 focuses on the development of the influence of top-down information on infant free-viewing of dynamic scenes. Chapters 3 and 4 both assess aspects of visual attention during real-world search. Specifically, Chapter 3 investigates the influence of underlying environmental regularities on real-world search efficiency and Chapter 4 asks how exploratory eye and head movements are differentially adapted to the varying demands on attention created by different tasks and environments.