My company is building an on-line map which displays moving objects (vehicles) and static objects (bus stops).
When the user hovers over an item, a tooltip with additional info about all the objects beneath the cursor appears.
Since the vehicles are moving, the objects beneath the cursor can change dynamically. The UX issue at hand is: how should the tooltip react?
- Change with the set of objects beneath the mouse pointer. Usability issue: Users might not have time to read all the information they are interested in before it disappears.
- Don't change the tooltip, until the mouse is moved. Usability issue: The tooltip might become inconsistent to what the mouse is actually hovering over.
- Use a timeout during which the tooltip is stable. Usability issue: Timeouts are always inappropriate for some users/use cases.
An added issue is the underlying data displayed in the tooltip might also change dynamically. The deviation (delay w/ regard to schedule) of a bus might change, it might finish its current trip and start a new one, etc. Considering options 2 and 3, should the tooltip keep these values up-to-date or just show the snapshot from when the mouse initially triggered the tooltip?
My gut feeling is to go with option 3 with dynamically updating data in the tooltip, but have not found real evidence from research or even anecdotal evidence to go one way or the other.
Edit: Many answers suggest we should drop tooltips in favor of a properties window that shows information for a vehicle the user has clicked/selected.
We already can do that in our UI, but in my opinion this is not an appropriate substitute for a tooltip. Clicking is not as effortless as hovering and also, it carries a different intent (i.e. that the user wants to use the selected object in some way), where as hovering is more "just look, don't touch" and less involved.
This is what selecting a vehicle in our UI looks like:
However, if many objects overlap at the point of click, the user has to click a second time to resolve the overlap and pick the vehicle she is interested in
I don't mind one or two click for selecting the exact vehicle if the user starts to perform a sequence of commands using that vehicle. However, a well made tooltip allows us to have a lightweight interaction for just glancing at the information very effortlessly.
I'm hoping this puts things in contexts and motivates why we would very much want a usable hovering interaction.