Аннотация:We introduce an integrated theory of learning and forgetting that has implications for training theory and practice. We begin with a review of skill acquisition research that argues that individuals employ different cognitive mechanisms when learning, which can be reliably associated with three stages of learning. This review leads to our proposed skill retention theory, which recommends a method to increase skill retention when designing systems, covering a range of system design issues, from interface design to training. We conclude with a discussion of how we might optimise skill retention based upon this approach. Specifically, we discuss how we might improve training by better spacing the iterations between training sessions to support proceduralisaion to improve skill retention.