Websites and intranets, as the
names suggest, involve nests and webs and inter/intra-connections of systems, data and
information which inter-act with each other. Making sense out of these systems
and information mumbo jumbo independently can be very tricky, sometimes
impossible, and even with the use of reductionism. Controlled vocabularies and
Metadata permit the IA to peruse through the network of relationships between
these systems. They provide a way to organize knowledge for subsequent
retrieval. They are used in subject
indexing schemes, subject
headings, thesauri, taxonomies and other forms of knowledge organization systems.
A controlled vocabulary is any defined
subset of natural language. It is a list of equivalent
terms in the form of a synonym ring, or a list
of preferred terms in the form of an authority file. Controlled
vocabulary schemes mandate the use of predefined, authorized terms that have
been preselected by the designer of the vocabulary, in contrast to natural
language vocabularies, where there is no restriction on the vocabulary.
Synonym rings connect a set of words
that are defined as equivalent for the purposes of data retrieval. These rings
can be used when a user enters a search term into a query, if the word is
contained in a synonym ring then the result will contain all the words within
the ring as-well. Therefor these rings can dramatically improve search results
by increasing the amount of recall of the search.
Authoritative files are lists of
preferred terms or accepted values. They help in keeping accurate and
consistent systems by reducing the allowed terms for a set domain. They can
include a synonym ring with one of the words select as being the preferred term
to use. These files can be useful with regards to indexes by making sure
information that can belong to similar terms can be categorized into only one
category; rather than spread over several. They can also be used to guide
people into using the preferred term over others,
for example when the variant term in an index is linked to a preferred
term.
Classification schemes are a
hierarchical arrangement of preferred terms aka Taxonomy (Hierarchy). These
schemes can be used in either front end (such-as the listing of a category on
the results of a search in yahoo or google) or back-end (such-as organizing and
indexing tags used by IAs, authors and Architects). There are many schemes that
can be used to classify the same information. The choice of scheme depends on
its intended application.
Metadata is data about other
data. It can be used in any sort of media to describe its contents and give it
additional information. It is definitional data that provides information about
or documentation of other data managed within an application or environment or
system. Metadata is usually stored behind the scenes. Metadata tags are used to
describe documents, pages, images, software, video and audio files, and other
content objects for the purposes of improved navigation and retrieval. One
example of Metadata in use is within web pages tag where it can be used freely
to add additional information describing the pages content. This data can be
used to help improve navigation and information retrieval on the page. Controlled
vocabularies are basically a defined subset of a language. Controlled
vocabularies are used to reduce the variability of expressions used to
characterize an item. It can come in the form of an authoritative file or a
list of equivalent terms.
Thesauri are collections
of categorized concepts, denoted by words or phrases that are related to each
other by narrower terms; wider terms and related term relations. They are a
book of synonyms, of including related and contrasting words and antonyms. They
allow for synonymous management by providing the preferred term amongst many
variants. It uses semantic relationships: Equivalence (like terms), Hierarchical
(sub categories), and Associative (related terms). They come in three forms
·
Classic- Full functional include
indexing and searching
·
Indexing- Allows indexes of preferred
terms
·
Searching -Is used at the point of
searching not indexing to manipulate the search performed. Users may be able to
specify their search terms by going narrower or broader.
The IA will need to
decide which of the above three forms to include in their site or intranet if
they choose to use a thesaurus. This decision should be based on how you intend
to use the thesaurus, and will definitely have major implications for design.
The thesaurus sets
itself apart from the simpler controlled vocabularies in its rich array of
semantic relationships. These relationships are of three types – Equivalence, Hierarchical
and Associative. When a number of terms represent the same concept, the
equivalence relationship clarifies which indexing term should be used. Hierarchical
relationship indicates the superordination and subordination of each preferred
term. This kind of relationship divides the information space
into categories and subcategories, relating broader and narrower concepts
through the familiar parent-child relationship. The associative
relationship is a
relationship between two concepts which do not belong to the same hierarchical
structure, although they have semantic or contextual similarities. The
relationship must be made explicit because it suggests to the indexer the use
of other indexing terms with connected or similar meanings which could be used
for indexing or searches. This relationship is often the trickiest, and by
necessity is usually developed after the IA has made a good start on the other
two relationship types. They are usually strongly implied semantic connections
that aren’t captured within the equivalence or hierarchical relationships.
Faceted
Classification is an analytic-synthetic classification scheme. It classifies
objects using multiple taxonomies that express their different
attributes or facets rather than classifying using a single taxonomy. A faceted classification system allows
the assignment of an object to multiple taxonomies (sets of attributes),
enabling the classification to be ordered in multiple ways, rather than in a
single, predetermined, taxonomic order. A facet comprises
"clearly defined, mutually exclusive, and collectively exhaustive aspects,
properties or characteristics of a class or specific subject". For example, a collection of books might be classified
using an author facet, a subject facet, a date facet, etc. Faceted
classification is used in faceted search systems that enable a user to
navigate information along multiple paths corresponding to different orderings
of the facets. This contrasts with traditional taxonomies in which the
hierarchy of categories is fixed and unchanging. In other words, once
information is categorized using multiple facets, it can also be retrieved
using multiple facets. Thus, a user would not be restricted to one identifying
search term in order to retrieve an item. He or she could use a single term or
link together multiple terms which increases his or her chances of retrieving
the exact information that is being sought.
Another real life implementation can be seen in http://wine.com
in which the various wine facets are type (red – merlot, pinot nor, malbec,
white – chrdonnay, muscadot, sparkling, etc…), region of origin (South African,
Argentinan, Carlifonian, Spanish, French, etc…), Winery/manufacturer (Clos du
Bois, Blackstone, etc…), Year (1968, 1996, 2002, 2014, etc…) and price ($5.99,
$9.99, $39.99, $156, etc…). This type of classification provides power and
flexibility. The interface can be tested and refined over time, while the
faceted classification provides an enduring foundation.
The Guided Navigation model encourages
users to refine or narrow their own searches based on metadata field s and
values built atop faceted classifications. Guided navigation has become the de
facto standard for e-commerce and product-related Web sites, from big box stores
to product review sites. But e-commerce sites aren’t the only ones joining the
facets club. Other content-heavy sites such as media publishers (e.g. The Financial Times),
libraries (such as NCSU
Libraries) and even non-profits (Urban Land Institute) are tapping into faceted search to make
their often broad range of content more findable. Essentially, guided
navigation or faceted search has become so ubiquitous that users are not only
getting used to it, they are coming to expect it.
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