Allen et al. (2015) studied students in a chemistry course at the University of California, Davis who were assigned a traditional textbook (448 students) and students in another section of the same course taught by the same instructor (478 students) that used Chemwiki (https://chem.libretexts.org/) as a primary course resource (an openly licensed wiki site that can be used as a textbook). They found no significant differences in outcomes between these students, as measured through pre-and post-tests on content covered in the course, the same midterm and final exams, and the administration of the Colorado Learning Attitudes about Science chemistry survey (Barbera, Perkins, Adams, & Wieman, 2008), which asks about students' "beliefs on learning chemistry, content of chemistry, structure of chemistry, and connection of chemistry to the outside world" (p. 942).