Student-directed models require considerably more interest and effort from the students and are criticized for consuming a lot of class time to cover smaller amounts of information at greater depths.
Social models provide a common ground between the two extremes.
The models listed below are classified by this three-tiered taxonomy. The Personalized System of Instruction is a mastery learning model, emphasizing independent study and proctored-testing. In Goal-Based Scenarios , instructors develop a motivational goal for learners that requires the application of certain skills and competencies. Relevant for most fields. Relevant for instructors wishing to spend less class time on basic course facts and concepts, opting instead for discussion and application to more elaborate problems.