Aza Raskin write about avoiding modalities.
“What’s wrong with modal overlays? In a word, they are modal: You are either interacting with the content or the overlay. Modal overlays don’t allow you to refer back and forth between two sources of information, or move fluidly between two actions. The second problem with modal overlays are that they are disconnected and disjoint from other overlays—knowing how to access one doesn’t yield a physical sense of how to access another one; they do not scale to give a unified, cohesive interface. ”
Link: Mobile Firefox and Designing Without Modal Overlays (azarask.in)
