This document defines and discusses information architecture and user experience. It begins by providing Morville and Rosenfeld's definition of information architecture as the structural design of shared information environments and the combination of organization, labeling, search, and navigation systems to support usability and findability. It then discusses criticisms that information architecture focuses on practical implementation over theory. The document outlines reasons why information architecture matters, such as reducing costs of finding, not finding, and redesigning information. It also discusses where information architects come from and their involvements in organizations like the IA Institute. Finally, it defines interaction design, human-computer interaction, and user experience, noting that user experience encompasses how users interact with products and is governed by user psychology