Facebook today said that it has started making changes to its News Feed based on the time people spend on individual posts. More changes will be coming over the next few weeks.

Clearly, time spent is important, but Facebook’s engineers have started to take a more nuanced view of the metric.

“When talking to people about the way they use their News Feed, we’ve found that it’s not as simple as just measuring the number of seconds you spend on each story to understand if that piece of content resonated with you,” Facebook software engineers Ansha Yu and Sami Tas wrote in a statement today. “Some people may spend ten seconds on a story because they really enjoy it, while others may spend ten seconds on a story because they have a slow internet connection.

“We’ve discovered that if people spend significantly more time on a particular story in News Feed than the majority of other stories they look at, this is a good sign that content was relevant to them.”

Likes and comments surely help Facebook rank posts for placement in the News Feed, but now time spent in posts will play a more significant part of the equation. The change takes into consideration the cases when users might not feel like liking or commenting on a post, but merely look at a friend’s photo, the text that person typed out, and the comments.

Other social networks, like Twitter, have done less to curate their feeds, but Facebook engineers have taken many steps through the years to make the most of that online real estate. Going forward, Facebook is making that content even more reflective of the way users behave.