adding notes and nodes along a line graph like google analytics, adding pins to map locations, establishing a reference point with additional information. So: A little thing that indicates, and clicking gives you a little more data, which may well NOT be in the little icon, hence it's not just an Icon (which see) and is a different item. ALSO see the eReader project where the highlight can be selected and show more info (not a Tooltip, though, as that is limited, read only, etc.)
This is not a tooltip. Deliberate action needed to reveal the additional info, or always there. tooltips are transient, initiated by hover or automatically presented when the system determines the user needs help -- such as first time, or a change in the system since last visit (put these notes over there when done here). The info in a tooltip is also a helpful sort of label or content add on. It is not content itself which it should be in an annotation.
Problem
A data point in a dense array, or within a graphical representation of a set of information, may be selected to show additional information.
Solution
Graphical information displays -- such as maps and graphs -- are often the clearest, most information-dense way of displaying a set of data. However, conventional methods of drilling in deeper such as the Link or Button are unsuitable for these items.
A special type of widget is used instead, exemplified by the "pinpoint." An iconic element points to the
Variations
Label all the time (gmaps desktop)
Reveal label - in place (gmaps as I have it now)
Reveal label - somewhere else (strip off to the side, GPS60)
Interaction Details
When available, hover or click to see the revealed label. Over...
Click to see the details... or if you revealed a label, click the label to see more details (SEE the other page!)
Has to get out of the way...
Presentation Details
Must clearly point at the location referenced
Antipatterns