This collection of research on object perception focuses on holistic and featural properties of objects, the mechanisms that produce such properties, how people choose one type of property over another, and how such choices are improved during the course of child development. The contributions consider alternative perceptual characterizations, the way in which such properties are represented in the mind, how particular properties are more useful in some kinds of tasks that humans perform, and how the developing child learns to cope with different properties in choosing among alternatives to optimize task performance. These papers were written by specialists for specialists in experimental, cognitive, and developmental psychology.