You can enter topic:David to search for articles with David in the title. This is a reasonably fast search. If I search my Bible Dictionaries collection, it takes you right to the relevant articles in your first 5 articles.,
The problem is that it also insists on still searching the rest of the library, even though I told it only to search the Bible Dictionaries. It returns nothing, but it takes about 1 additional second to do this. It also takes another second to search My Content. When I am limiting my search to a collection and only searching by topic, why should it also search these other parts of the library? This slows up the whole search, which would otherwise be very quick.
