I was thinking of using a searchable\predictive text combo box to allow a user selecting an item from a very long list of items with long names (lets say from a list of 200 items). I thought it would be a good idea to display a tool tip on the items, with the item's description to allow the user to understand better what the item is. People in my organisation think that in web applications this is rather a non standard behaviour, where is I know that in desktop applications this practice was used. What do you think? Any design patters that you are familiar with associated with this?
While it is kind of non-standard (don't think I've encountered such a thing before) it's easy enough to think of something that would work. Two things to look out for:
Dont't have stuff overlap. Since this is about information we don't want to obscure information.
Clearly surface the functionality. It is non standard, but we can use standard patterns in a way that communicate how this thing works.
As soon as the user starts typing, start showing hits in a list below the search/combobox and highlight the first one. Next to the list, show the detailed information about the selected hit. When the user hovers over other items (or highlights them using up and down) in the list, update the details-box accordingly.