So it's mentioned frequently how icons and buttons might not always be 100% intuitive in what they mean, and that ideally they should be accompanied by a label.
What about a tooltip, like in HTML when you have the
<dfn /> tag? Essentially, it underlines a word, and if you hover over it for a second, it'll show a tiny label popup with the explanation. Moving the mouse removes the tooltip.
Is this a good idea, usability-wise, as an alternative to a label (for constrained real-estate environments, like Android screens)? Also, should I have no delay, a short delay, or a long delay before showing the information? What about an option to disable the labels?
Edit: Just to be clear, this is for a non-HTML environment; but I'm asking in general about tooltips, and how to make them usable.