Of the 91 publications selected for this review, 46 specifically commented on the inclusion of a token system and three commented specifically on choosing not to include a token system. The remaining forty-two publications do not include any specific information about token systems. Instructors chose to provide tokens in their specifications grading systems by providing a set number of tokens to each student at the beginning of the course (seven examples) , by providing opportunities for students to earn tokens throughout the term of a course (fourteen examples) , or by combining both aforementioned approaches (seventeen examples) . In the earn-only or combination approaches, students were given opportunities to earn tokens by a variety of means such as completing metacognitive reflection assignments or completing low-stakes course activities such as readings and homework. In all token systems described, students were given the option to use tokens for additional attempts at assignments (either through revision or attempting a new version of an assignment such as a quiz), for flexibility on assignment deadlines, or both. In six examples, students could also use tokens to earn back credit on a low-stakes assignment that they missed originally or to replace attendance credit lost for missing class when attendance was required . In all cases, the choice of how to use tokens was left with the students, although instructors did provide encouragement to use tokens as needed and reminders of how to do so.