The study was first revealed at a Harvard faculty meeting Tuesday night. According to The Globe, a federally mandated university board that monitors faculty's research approved the study, which set up secret cameras in 10 lecture halls last spring.
Here's how the study worked, according to The Globe: "The cameras snapped an image every minute, and a computer program scanned the images to count how many seats were empty and how many were filled during lectures."
The study has drawn criticism from both Harvard students and faculty due to the secretive nature of the recordings, although all photos have now been destroyed. According to the Associated Press, "Harvard administrators say students and teachers were not notified because researchers did not want to introduce potential bias into the study."
The Globe reports that Harvard president Drew Faust told the faculty that she takes the matter "very seriously" and that the university will be investigating the study.
Harvard recently updated its privacy rules after it was revealed last year that the university anonymously accessed faculty emails while investigation a student cheating scandal.