We Don't Know How Much Screen Time Is Too Much Because the Science Isn't Totally ThereA new study says that the way that the effects of screen time have been studied has lead to a lot of conflicting answers.

Ahead of last fall's rollout of Apple's Screen Time feature, which shows you just how long you've spent staring at your phone, CEO Tim Cook revealed that he had been testing it out. It had inspired him to make some changes, particularly when it came to cutting down on the amount of notifications he was being bombarded with.

"I think it has become clear to all of us that some of us are spending too much time on our devices," Cook said inconversationat Fortune's CEO Initiative conference in San Francisco. "And so what we have tried to do is then think through pretty deeply well, how could we help with that? Because honestly, we have never wanted people to overuse our products. We are not about usage. We want people ... to be empowered from them and to be able to do things they couldn't do otherwise. … If you are spending all the time on your phone, you are spending too much time."

Anecdotally, you know that scrolling through Twitter or Instagram into the wee hours is probably not the best idea if you want to be alert and productive the next day. However, the question of how much time is too much has always been something of a moving target.

Related:These Glasses Block You From Seeing Screens, But There Are Things You Can Do to Cut Screen Time Now

But according tofindingsfrom Oxford University researchers Amy Orben and Andrew Przybylski, the science that has been used to figure out how much of an impact screen time has on our overall well-being isn't as solid as it could be -- and often looks at wide swaths of participants in a very short amount of time -- has lead to a lot of conflicting answers depending on how the studies have been carried out.

"Unfortunately, the large number of participants in these designs means that small effects are easily publishable and, if positive, garner outsized press and policy attention," Orben and Przyblyski wrote, finding that on that whole, screen time isn't consistently positive or negative. "The nuanced picture provided by these results is in line with previous psychological and epidemiological research suggesting that the associations between digital screen-time and child outcomes are not as simple as many might think."

So while there isn't a definitive scientific answer for the time being, our best advice would be to use devices in moderation. One thing we can definitely recommend, however, is no Facebook stalking at 3 a.m.