1. Are badges useful in education?: it depends upon the type of badge and expertise of learner;Abramovich;Educational Technology Research & Development,2013
2. Class differences: Online education in the United States;Allen,2010
3. How do teachers support students' motivation and learning in their classrooms?;Anderman;Teachers College Record,2011
4. How classroom environment and student engagement affect learning in internet-based MBA courses;Arbaugh;Business Communication Quarterly,2000
5. Student engagement, visual learning and technology: Can interactive whiteboards help?;Beeland,2002