Previews and overviews in digital libraries: Designing surrogates to support visual information seeking

To aid designers of digital library interfaces, we present a framework for the design of information representations in terms of previews and overviews. Previews and overviews are graphic or textual representations of information abstracted from primary information objects. Previews act as surrogates for one or a few objects and overviews represent collections of objects. A design framework is elaborated in terms of the following three dimensions: (1) what information objects are available to users, (2) how information objects are related and displayed, and (3) how users can manipulate information objects. When utilized properly, previews and overviews allow users to rapidly discriminate objects of interest from those not of interest, and to more fully understand the scope and nature of digital libraries. This article presents a definition of previews and overviews in context, provides design guidelines, and describes four example applications.