The document discusses the importance of usability testing in technology product development. It defines usability and outlines several key aspects of usability including learnability, efficiency, errors and satisfaction. The document also describes different methods of usability testing such as heuristic evaluation, formative evaluation and testing prototypes with representative users and tasks. It notes that usability testing is particularly important during the design and development phases of a project. Finally, it discusses how emerging technologies are presenting new challenges for usability testing.