The latest of several studies to look into the relationship between Facebook use and low grades has a counterintuitive twist — some kinds of Facebook use are correlated with higher GPAs.

"Facebook use in and of itself is not detrimental to academic outcome," says study author Reynol Junco, a professor at the Lock Haven University of Pennsylvania. "It depends how it's used."

The study, published last week in Computers in Human Behavior, analyzes 1,839 college students' survey data about Facebook use and actual grades (as opposed to self-reported grades). It also takes into account students' high-school GPAs.

On average, students say they spend 106 minutes on Facebook per day. Each increase of 93 minutes beyond 106 minutes correlates with a GPA decrease of .12 grade points — statistically significant, but not dramatic when applied to a real-world situation.

"You have to spend an inordinate amount of time on Facebook for it to be related to GPA in a way that is shocking," Junco says.

It makes sense that a drop in grades would be caused by students who let Facebook time cut into study time. But the data shows no correlation between time spent on Facebook and time spent studying.

All Facebook activities do not have the same relationship with grades. Posting status updates and using Facebook chat generally mean a lower GPA, while checking to see what friends are up to and sharing links suggest a higher GPA. In other words, social Facebook activities were correlated with lower grades and information-related Facebook activities were correlated with higher grades.

This doesn't necessarily mean forgoing Facebook status updates and chat is likely to improve a student's grades. Nothing in the study implies cause and effect. Instead, it seems that what's important about Facebook in an educational context has very little to do with how much time you spend on it.

Junco thinks there are ways Facebook can be used effectively in an educational context — which is why he sets up Facebook groups for each of his classes to continue discussion online.

"What I like best about it is that we’re using a technology that students already use,” he says.