No matter how much you pay someone. Or how good your benefits are. Or even how much you try to make work "fun." Everyone still chooses how much of themselves they are going to give from day to day. That's why engagement is such a squishy concept.

That's also why we laid out the only observable measure of engagement in our post last week. 

And now that you know how to truly tell if someone's engaged (reminder: sometimes it's the ones you'd least expect), you can take that information and put it to good use by adopting these 5 research-backed ways to improve engagement.