Your Textbook Knows You're Going to Fail

College professors no longer need to ask their class for an earnest show of hands to answer the dreaded question, "who did the reading?" Thanks to digital textbooks, instructors are able to tell exactly how much you've read, how long it took you to read it, and plenty more about your study habits. And whatever students might think about their speed-skimming abilities, a new study shows the more time college students spend reading their textbooks, the better their course grades.

The study followed 236 Texas A&M University-San Antonio undergraduates who used digital textbooks to see what type of data could best predict success in the course. Did it matter most how much time students spent reading? Or was it more important whether they "actively read"—doing things like using highlighters? It turned out that the most important thing was the sheer number of minutes spent reading—that number was better at determining whether a student would do well in class than even how they'd previously performed academically.