Modern Information Retrieval Chapter 10: User Interfaces and Visualization

Contents

  
3. The DLITE Interface

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The DLITE system [#!cousins97!#,#!cousins97b!#] makes a number of interesting design choices. It splits functionality into two parts: control of the search process and display of results . The control portion is a graphical direct manipulation display with animation (see Figure). Queries, sources, documents, and groups of retrieved documents are represented as graphical objects. The user creates a query by filling out the editable fields within a query constructor object. The system manufactures a query object, which is represented by a small icon which can be dragged and dropped onto iconic representations of collections or search services. If a service is active, it responds by creating an empty results set object and attaching the query to this. A set of retrieval results is represented as a circular pool, and documents within the result set are represented as icons distributed along the perimeter of the pool. Documents can be dragged out of the results set pool and dropped into other services, such as a document summarizer or a language translator. Meanwhile, the user can make a copy of the query icon and drop it onto another search service. Placing the mouse over the iconic representation of the query causes a `tool-tips' window to pop up to show the contents of the underlying query. Queries can be stored and reused at a later time, thus facilitating retention of previously successful search strategies.

  

Figure: The DLITE interface [#!cousins97!#].

A flexible interface architecture frees the user from the restriction of a rigid order of commands. On the other hand, as seen in the SuperBook discussion, such an architecture must provide guidelines, to help get the user started, give hints about valid ways to proceed, and prevent the user from making errors. The graphical portion of the DLITE interface makes liberal use of animation to help guide the user. For example, if the user attempts to drop a query in the document summarizer icon -- an illegal operation -- rather than failing and giving the user an accusatory error message [#!cooper95!#], the system takes control of the object being dropped, refusing to let it be placed on the representation for the target application, and moves the object left, right, and left again, mimicking a `shake-the-head-no' gesture. Animation is also used to help the user understand the state of the system, for example, in showing the progress of the retrieval of search results by moving the result set object away from the service from which it was invoked.=-1

DLITE uses a separate Web browser window for the display of detailed information about the retrieved documents, such as their bibliographic citations and their full text. The browser window is also used to show Scatter/Gather-style cluster results and to allow users to select documents for relevancefeedback. Earlier designs of the system attempted to incorporate text display into the direct manipulation portion, but this was found to be infeasible because of the space required [#!cousins97b!#]. Thus, DLITE separates the control portion of the information access process from the scanning and reading portion. This separation allows for reusable query construction and service selection, while at the same time allowing for a legible view of documents and relationships among retrieved documents. The selection in the display view is linked to the graphical control portion, so a document viewed in the display could be used as part of a query in a query constructor.=-1

DLITE also incorporates the notion of a workspace, or `workcenter,' as it is known in this system. Different workspaces are created for different kinds of tasks. For example, a workspace for buying computer software can be equipped with source icons representing good sources of reviews of computer software, good Web sites to search for price information and link to the user's online credit service. interface design!DLITE|) DLITE|)