The literature shows that the vast majority of students report open textbooks to be of the same or better quality than the commercial textbooks they have used.

Fischer, Hilton, Robinson, & Wiley (2015) studied a large sample of students from six colleges and four community colleges in the US. Students in the treatment group (N=1087) used an open textbook or other OER in their courses, and students in the control group (N=9264) were asked to purchase traditional textbooks for different sections of the same courses. The authors found that the students using OER did just as well or better in most of the courses studied in terms of course grades and completion rates.