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Conceptual analysis of Web metadata [Kent & Neuss 1994] [Neuss & Kent 1995] provides a formal mechanism for<br />

the automatic categorization and classification of documents. By apply<strong>in</strong>g conceptual scales to metadata, faceted<br />

conceptual spaces can be constructed. In these concept spaces, various properties collocate Web document-like objects<br />

accord<strong>in</strong>g to common characteristics. Conceptual scal<strong>in</strong>g is an <strong>in</strong>terpretative act with a highly <strong>in</strong>teractive user<br />

<strong>in</strong>terface component. This paper advocates a method called conceptual brows<strong>in</strong>g as a navigation and structural<br />

brows<strong>in</strong>g technique. It is based on the notion of “conceptual distance,” a formal similarity metric for documents. The<br />

algorithmic def<strong>in</strong>ition of similarity allows for an <strong>in</strong>cremental brows<strong>in</strong>g of the conceptual vic<strong>in</strong>ity of a document or a<br />

class of documents.<br />

Conceptual Space<br />

Conceptual Knowledge Process<strong>in</strong>g<br />

Conceptual knowledge process<strong>in</strong>g [Wille 1982] [Ganter & Wille 1989] is a relatively new discipl<strong>in</strong>e aris<strong>in</strong>g out of the<br />

mathematical theory of lattices and the calculus of b<strong>in</strong>ary relations. It is closely related to the areas of knowledge<br />

representation <strong>in</strong> computer science and cognitive psychology. Conceptual knowledge process<strong>in</strong>g provides for the<br />

automatic classification of both knowledge and documents via representation of a user's faculty for <strong>in</strong>terpretation as<br />

encoded <strong>in</strong> conceptual scales. Such conceptual scales correspond to the facets of synthetic classification schemes, such<br />

as Ranganathan's Colon classification scheme, <strong>in</strong> library science. Conceptual knowledge process<strong>in</strong>g uses objects,<br />

attributes and formal concepts as its basic constituents. Objects and attributes are connected through has-a <strong>in</strong>cidence<br />

relationships, while formal concepts are connected through is-a subtype relationships. In many contexts appropriate<br />

for Web resources, the objects are document-like objects and the attributes are properties of those document-like<br />

objects which are of <strong>in</strong>terest to the Web user. Conceptual knowledge process<strong>in</strong>g uses formal concepts as its central<br />

notion and uses concept lattices as an approach to knowledge representation [Wille 1992]. A formal concept (also<br />

called a conceptual class or category) consists of a collection of entities or objects exhibit<strong>in</strong>g one or more common<br />

characteristics, traits or attributes. Formal concepts are logically characterized by their extent and <strong>in</strong>tent. The extent of<br />

a concept is the aggregate of entities or objects which it <strong>in</strong>cludes or denotes. The <strong>in</strong>tent of a concept is the sum of its<br />

unique characteristics, traits or attributes, which, taken together, imply the formal concept. The process of<br />

subord<strong>in</strong>ation of concepts and collocation of objects exhibits a natural order, proceed<strong>in</strong>g top-down from the more<br />

generalized concepts with larger extent and smaller <strong>in</strong>tent to the more specialized concepts with smaller extent and<br />

larger <strong>in</strong>tent. This is-a relationship is a partial order called generalization-specialization. Concepts with this<br />

generalization-specialization order<strong>in</strong>g form a class hierarchy called a concept lattice. This is the formal representation<br />

for conceptual knowledge. The use of formal concepts as a conceptual structur<strong>in</strong>g mechanism corresponds to the use<br />

of similarity clusters <strong>in</strong> <strong>in</strong><strong>format</strong>ion retrieval, although foundationally, formal concepts are based more on logical<br />

implication rather than a nearness notion.<br />

A concept space is a named substructure of a concept lattice. In a precise mathematical sense, a concept space is a<br />

“distributed formal concept.” The ma<strong>in</strong> purpose for the concept space notion is to provide for the organization and<br />

customization by the user of their own <strong>in</strong><strong>format</strong>ion space. The representational mechanism of a concept space serves<br />

as a firm foundation for the basic paradigms of Internet/<strong>in</strong>tranet resource discovery and wide area <strong>in</strong><strong>format</strong>ion<br />

management systems; both organization-navigation and search-retrieval [Kent & Bowman 1995]. The use of<br />

conceptual space is a natural outgrowth of the orig<strong>in</strong>al conceptual knowledge process<strong>in</strong>g approach for structur<strong>in</strong>g and<br />

organiz<strong>in</strong>g the networked <strong>in</strong><strong>format</strong>ion resources <strong>in</strong> the World Wide Web [Kent & Neuss 1994]. Conceptual space<br />

forms its nam<strong>in</strong>g mechanism via conceptual views. A conceptual view is a name for a formal concept with<strong>in</strong> a concept<br />

lattice. Conceptual views are created by any of the follow<strong>in</strong>g methods: (1) view def<strong>in</strong>itions <strong>in</strong> terms of meets and jo<strong>in</strong>s<br />

of other views, meets of attributes, and jo<strong>in</strong>s of objects; and (2) view def<strong>in</strong>itions (virtual views) <strong>in</strong> terms of the meetvectors<br />

of apposition concept spaces or the jo<strong>in</strong>-vectors of subposition concept spaces. Virtual views have applications<br />

<strong>in</strong>: (i) the <strong>in</strong>terpretation by conceptual scal<strong>in</strong>g; (ii) the parallel implementation of conceptual knowledge process<strong>in</strong>g,<br />

and (iii) collaboration <strong>in</strong> distributed <strong>in</strong><strong>format</strong>ion systems. Virtual meet views are useful <strong>in</strong> conceptual scal<strong>in</strong>g when we<br />

use various facets of <strong>in</strong><strong>format</strong>ion <strong>in</strong> order to organize a conceptual space over an <strong>in</strong><strong>format</strong>ion system. For<br />

collaboration, we can merge remote public data <strong>in</strong>terpretation, as represented by conceptual scal<strong>in</strong>g, with local private<br />

data <strong>in</strong>terpretation. This provides one approach for the private customization and shar<strong>in</strong>g of public data. Accord<strong>in</strong>g to

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