Economics and political science sophomore Alexander Cohen, 20, checks his Facebook once or twice a day for about 30 minutes on his computer. He checks it once an hour for about a minute on his phone. 

But the time he spends on Facebook, he said, has no effect on his grades or his studies.

"I keep it on in the background of my computer, and if someone messages me, I answer them," Cohen said.

However, according to a recent study by a UF graduate, Cohen is not in the norm.

Reynol Junco, 40, who graduated from UF in 1994 with a bachelor's degree in psychology, conducted a study that showed the time spent on Facebook was negatively related to overall college GPA.

His findings were recently published in a paper called "Too much face and not enough books: The relationship between multiple indices of Facebook use and academic performance."

The study gathered findings from 1,839 students from one university. Junco would not disclose the specific university for ethical reasons.

In a survey, Junco asked students about the average amount of time they spent on Facebook and how frequently they checked the website.

Junco, a professor at Lock Haven University in Pennsylvania, also analyzed what Facebook activities students frequented. Students' grades were accessed through the university registrar, Junco said.

Junco also looked at different Facebook activities and found some had a positive relationship with grades, such as sharing links and checking friends' profiles.

But posting status updates had a negative correlation.

Using Facebook for socializing is negatively related to GPA, while using Facebook for collecting and sharing information is positively related, Junco said.

Sociology sophomore Elesa Paschke, 19, checks her Facebook every hour for a minute or less. She checks for notifications and posts links on people's walls but rarely updates her status or goes through friends' statuses.

"I think Facebook has benefited me because I learn about things I wouldn't normally search for," Paschke said.

The study did not find a strong link between the time spent studying and the time spent on Facebook.

"Facebook does not prevent me from studying," said accounting senior Austin LeFevre, 21. LeFevre goes on Facebook to post links, check friends' activities and talk to friends about three times a day for two minutes to 20 minutes.

Although the study may have been statistically significant, the real-world impact was minimal, Junco said. For example, the average time a student spent on Facebook was 106 minutes. Every 93 minutes above that time, that student's GPA would decrease .12 points, which is not a big relationship, Junco said.

There have been three other published studies of Facebook use and academic performance, but this one is the first to use a large sample, include better estimates of time spent on Facebook, connect the survey data to actual grades and use high school GPA as a control, Junco said.

One of the previous published studies found no relationship between Facebook use and grades.

Junco said he thought he would have similar findings. However, he did not.

"It is not whether or not students use Facebook, but how they use it, that is important," Junco said.