Grounding in the UI — Knowing Exactly Where to Click
A computer-use agent can perceive the screen and decide "click Submit," but it still has to answer a deceptively hard question: where exactly is Submit, and how do I act on precisely that spot? This UI grounding problem — connecting a decision to a precise screen location and element — is where many computer-use agents stumble, because a click a few pixels off hits the wrong thing. This post is about how agents locate and target UI elements reliably.
Deciding 'click Submit' is easy; knowing exactly where Submit is and clicking precisely there is the grounding problem — where a click a few pixels off hits the wrong thing. Coordinate vs element-based vs set-of-marks grounding, why precise localization is hard for vision, and why mis-clicks are a top failure mode.