The document discusses research on the use of e-textbooks versus printed textbooks. It provides an overview of the history of e-textbooks and their increasing use. Several studies have found that student performance and comprehension do not differ significantly between e-textbooks and printed textbooks. However, some research indicates that people understand and remember better when reading printed texts rather than screens. Both e-textbooks and printed textbooks have advantages and disadvantages for student learning. The document explores these challenges and affordances in more detail.