The Pew Research Center is one of the largest sources of information on how Americans use technology like smartphones, social media, and broadband networks. This doesn't just mean collecting data, it means figuring out which questions are meaningful — something that can be revealing in its own right. Today, the center released a brief report on how often American adults go online, adding a new survey option: "almost constantly."

This "almost constantly" phrasing first showed up in a report on teens in April, with 24 percent of respondents selecting it. This survey found that 21 percent of adults believe they're almost constantly online, with demographic variations that echo several of its other tech surveys. Young adults are more likely to report it, as are people with higher income and education levels, and people over 65 are fairly unlikely to do so. Only 6 percent of them are almost always online, compared to 36 percent of 18- to 29-year-olds.

The really interesting question here isn't how many of us never leave the internet, it's how people define constant use. Pew generally lets respondents interpret options without further explanation, but it seems clearly related to smartphones and other mobile internet devices. An earlier survey contains some very similar questions about cellphones, asking smartphone users if they use the phone's apps "continuously" — 27 percent said they did.

The easiest interpretation is that "going online" means having some kind of online notification system, even if you're not actively paying attention to it. That could include anything from streaming music on Spotify to getting email push alerts, and it's closer to our relationship with something like a telephone; we're not "on the phone" for 24 hours a day, but the phone still changes our lives.

This breaks down a bit when you consider some of the other questions, though. In the smartphone survey, 14 percent of users reported using their phone's browser continuously, which means they're either using an unusual definition of the word or spending a lot of time staring at a tiny screen. Pew notes that 8 percent of people who don't use mobile internet options are "almost constantly" online — a small category, but one that makes sense for anyone who works long hours on a computer or devotes all their free time to online gaming.

Finally, there's the question of how many hours someone has to clock. Is almost constant use having a job that involves staring at a screen all day? Is it hanging out on Reddit after work but spending your weekends offline? Is it actively using some kind of internet-enabled service for every waking hour? Perhaps this question will only truly be answered when we've made the leap to some ultra-realistic virtual world — at which point we'll be more worried about the people who aren't constantly online.