Contrived experiences are simulations or representations of real-world experiences that are used in teaching when it is not possible to bring the real thing into the classroom. There are several types of contrived experiences that can be used, including models, mock-ups, specimens, objects, and simulations. Contrived experiences are used to overcome limitations of space and time, to focus learning on specific parts or processes, and to help students understand concepts that are otherwise inaccessible or abstract. Some purposes of using simulations and games in education include developing changes in attitudes, preparing students for new roles, increasing understanding of current roles, and motivating learners.