Chapter: Learning and Retention

Learning and retention are important for design. Learning provides performance improvements, sometimes dramatic improvements with practice on a task or with an interface. These improvements can make designs that appear too slow on first use to become more usable and remove errors in performance. Learning, the rate at which it occurs, the stages of learning, how to predict it, and when learning transfers are all important aspects of human behavior for design. Retention is also important. The retention curve is similar to the learning curve in that dramatic skill loss is possible with the passage of time, which can be dangerous. The knowledge we have about learning and retention yields numerous suggestions for system design, including how to evaluate interfaces (with trained or novice testers), how and how often to train (to retain declarative knowledge and to create proceduralized knowledge where possible), and how to present information (so that it can be learned).