Modern Information Retrieval Chapter 10: User Interfaces and Visualization

Contents

     
6. Integrating Scanning, Selection, and Querying

interface design!integrating operations integrating search operations

User interfaces  for information access in general do not do a good job of supporting strategies, or even of sequences of movements from one operation to the next. Even something as simple as taking the output of retrieval results from one query and using them as input to another query executed in a later search session is not well supported in most interfaces.

Hertzum and Frokjaer [#!hertzum96!#] found that users preferred an integration of scanning and query specification in their user interfaces. They did not, however, observe better results with such interactions. They hypothesized that if interactions are too unrestricted this can lead to erroneous or wasteful behavior, and interaction between two different modes requires more guidance. This suggests that more flexibility is needed, but within constraints (this argument was also made in the discussion of the SuperBook system in section ).

  

Figure: A view of query history revision in the Web-based version of the Melvyl bibliographic catalog. Copyright ©, The Regents of the University of California.

Melvyl system

There are exceptions. The new Web version of the Melyvl  system provides ways to take the output of one query and modify it later for re-execution (see Figure ). The workspace-based systems such as DLITE  and Rooms  allow storage and reuse of previous state. However, these systems do not integrate the general search process well with scanning and selection of information from auxiliary structures. Scanning, selection, and querying needs to be better integrated in general. This discussion will conclude with an example of an interface that does attempt to tightly couple querying and browsing.

interface design!Cat-a-Cone|( Cat-a-Cone|(

The Cat-a-Cone  interface integrates querying and browsing of very large category hierarchies with their associated text collections. The prototype system uses 3D+animation interface components from the Information Visualizer  [#!card96!#], applied in a novel way, to support browsing and search of text collections and their category hierarchies. See Figure . A key component of the interface is the separation of the graphical representation of the category hierarchy from the graphical representation of the documents. This separation allows for a fluid, flexible interaction between browsing and search, and between categories and documents. It also provides a mechanism by which a set of categories associated with a document can be viewed along with their hierarchical context.

  

Figure: The Cat-a-Cone interface for integrating category and text scanning and search [#!hearst97b!#].

Another key component of the design is assignment of first-class status to the representation of text content. The retrieved documents are stored in a 3D+animation book representation [#!card96!#] that allows for compact display of moderate numbers of documents. Associated with each retrieved document is a page of links to the category hierarchy and a page of text showing the document contents. The user can `ruffle' the pages of the book of retrieval results and see corresponding changes in the category hierarchy, which is also represented in 3D+animation. All and only those parts of the category space that reflect the semantics of the retrieved document are shown with the document.

The system allows for several different kinds of starting points. Users can start by typing in a name of a category and seeing which parts of the category hierarchy match it. For example, Figure shows the results of searching on `Radiation' over the MeSH terms in this subcollection. The word appears under four main headings (Physical Sciences, Diseases, Diagnostics, and Biological Sciences). The hierarchy immediately shows why `Radiation' appears under Diseases -- as part of a subtree on occupational hazards. Now the user can select one or more of these category labels as input to a query specification.

  

Figure: An interface for a starting point for searching over category labels [#!hearst97b!#].

Another way the user can start is by simply typing in a free text query into an entry label.This query is matched against the collection. Relevant documents are retrieved and placed in the book format. When the user `opens' the book to a retrieved document, the parts of the category hierarchy that correspond to the retrieved documents are shown in the hierarchical representation. Thus, multiple intersecting categories can be shown simultaneously, in their hierarchical context. Thus, this interface fluidly combines large, complex metadata, starting points, scanning, and querying into one interface. The interface allows for a kind of relevance feedback, by suggesting additional categories that are related to the documents that have been retrieved. This interaction model is similar to that proposed by [#!agosti92!#].

Recall the evaluation of the Kohonen feature map representation discussed in section . The experimenters found that some users expressed a desire for a visible hierarchical organization, others wanted an ability to zoom in on a subarea to get more detail, and some users disliked having to look through the entire map to find a theme, desiring an alphabetical ordering instead. The subjects liked the ease of being able to jump from one area to another without having to back up (as is required in Yahoo!) and liked the fact that the maps have varying levels of granularity.

These results all support the design decisions made in the Cat-a-Cone. Hierarchical representation of term meanings is supported, so users can choose which level of description is meaningful to them. Furthermore, different levels of description can be viewed simultaneously, so more familiar concepts can be viewed in more detail, and less familiar at a more general level. An alphabetical ordering of the categories coupled with a regular expression search mechanism allows for straightforward location of category labels. Retrieved documents are represented as first-class objects, so full text is visible, but in a compact form. Category labels are disambiguated by their ancestor/descendant/sibling representation. Users can jump easily from one category to another and can in addition query on multiple categories simultaneously (something that is not a natural feature of the maps). The Cat-a-Cone has several additional advantages as well, such as allowing a document to be placed at the intersection of several categories, and explicitly linking document contents with the category representation.

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