Wrote an article on the empathy gap. Here's a blurb:
"Mind the gap" is a phrase issued to rail passengers, instructing them to heed the spatial gap between the train door and the station platform. The empathy gap is fairly analogous. It describes the large gap between what software architects (designers and developers alike) think their users need, and what their users actually need.
If you'd like, you can read the full article here.