taxonomies for information
Post on 18-Oct-2014
1.380 views
DESCRIPTION
TRANSCRIPT
Taxonomies for Information & Knowledge
Management Architectures
Denise A. D. Bedford, Ph.D.Senior Information Officer - Information Solutions Group Corporate Information Systems
The World Bank Group
Special Libraries Association – DC Chapter – February 4, 2003
Who Needs to Understand Taxonomies?
Anyone who has been charged with the task of organizing information, regardless of the context – Brick & Mortar, KM system, ILS, Portal, Records Management System, …….
You may have been trained to work with a variety of Information Organization tools or trained in bibliographic control principles
It is probably the case that these tools were not presented as taxonomies – perhaps as rules, as record formats…
Professional literature also presents a confusing, often, simplistic view of taxonomies Assumes that a taxonomy is only hierarchical Fails to provide a clear distinction between the structures & uses of
classification schemes, subject headings, thesauri & metadata
Information Management System Architectures
The underlying architecture of a full bibliographic control system, records management system, a metadata repository or corporate information architecture is complex
Taxonomies are essential structures in all information management systems
Information managers, librarians, information architects, knowledge architects, records managers need to be able to:
Understand the different kinds of taxonomies Have sufficient familiarity with their purpose to select the right kind
of taxonomy for an application
Taxonomy Basics
There are four types of taxonomies Flat Hierarchical Faceted Network
Some are explicit/visible, others are implicit/invisible
There are significant design consideration when implementing each different type
Let’s review each quickly
Definition of a Taxonomy
“System for naming and organizing things into groups that share similar characteristics” Jean Graef, Montague Institute
Taxonomy
Architectures Applications
Taxonomy Basics
Four types of taxonomies
Flat
Hierarchical
Faceted
Network
Flat Taxonomy Structure
Energy Environment Education Economics Transport Trade Labor Agriculture
Type 1: Flat Taxonomies
Flat taxonomies group content into a controlled set of categories
no inherent relationship among the categories in a flat taxonomy -- they are co-equal members of a single structure
can move from one category to another without having to think about the relationship between them
concept of a flat taxonomy may be counter intuitive to some
Consider how often you use flat taxonomies everyday
alphabetical listings of people in a directory of expertise a pull-down menu of country names or geographical regions simple alphabetical listings of product groupings
Designing Flat Taxonomies
Flat taxonomies are easy to create
Flat taxonomies do not require complex interface design and extensive usability testing
We have learned from usability engineers how to implement flat taxonomies
Flat taxonomies used for explicit information structures generally should consist of 30 or fewer categories;
More than 30 categories may be presented in a flat taxonomy, if the categories are intuitive to users (i.e. lists of countries, states, languages, etc.);
Explicit Flat Taxonomies
Amazon.com’s pull down list of product categories & horizontal list of stores- http://www.Amazon.com
Nordstom.com’s alphabetical list of brand names - http://www.nordstrom.com
Microsoft PowerPoint’s global functional menu & pull down menu
Water Resources Directory of Expertise list of keywords - http://www.nceas.ucsb.edu/exp/
Bartleby.com’s extensive picklists of reference, verse, fiction & non-fiction listings -- http://www.bartleby.com/
CyberDewey’s alphabetical index to sections - http://www.anthus.com/CyberDewey/Dewey_index.html
Implicit Flat Taxonomies
Alphabetical list of water resource experts
Content inventories listed alphabetically by author
Rights management values (simple picklist)
Information disclosure status values (simple picklist)
Security classification scheme values (simple picklist)
Hierarchical Taxonomy
A hierarchical taxonomy is represented as a tree data structure in a database application. The tree data structure consists of nodes and links. In an RDBMSenvironment, the relationships become associations. In a hierarchical taxonomy, a nodecan have only one parent.
Type 2: Hierarchical Taxonomies Group content into two or more levels
Resemble tree structures when they are fully elaborated
Hierarchical categories typically have only one broader or parent category.
Relationships among categories in hierarchical taxonomies have particular meaning Relationship between a top level category & subcategory may mean
group membership or refinement of the top category by a particular characteristic or feature
Moving up the hierarchy means expanding or broadening the category Moving down the hierarchy means refining or qualifying the category
Explicit Hierarchical Taxonomies
Yahoo’s Web Site Directory - organized as a subject hierarchy - http://www.yahoo.com
Internet Public Library’s two-tier collection structure - http://www.ipl.org
Librarian’s Index to the Internet mixed hierarchy of topics and resource types - http://www.lii.org/
Ebay’s auction categories – http://www.ebay.com
CyberDewey’s progressive disclosure of Dewey Decimal classes - http://www.anthus.com/CyberDewey/CyberDewey.html
Albertson’s Shop By Aisle grocery categories or Shop A to Z grocery product - http://www.albertsons.com/store/categores
Implicit Hierarchical Taxonomies
Electronic news story published in XML NITF format International Press Telecommunications Council. News
Industry Text Format. Version 3.1 September, 2002. http://www.nitf.org/
Classification schemes for topic areas
Authority control lists for abbreviations & full names (aliases)
Records management hierarchical fileroom structures
Cross source topic reference structures
Designing Hierarchical Taxonomies
There is more than one way to implement a hierarchy:
Progressive disclosure of layers across sites or pages -- Ebay model
Cascading or expanding menus -- United Nations web site Pop-up menus linked to stationary menus -- United Nations web
site Category and subcategory labels in a multi-column display --
Nordstrom’s second level pages
Designing Hierarchical Taxonomies
Hierarchical taxonomies should:
have content at every level -- empty categories present empty value to users
be less than four levels deep in most cases
be at least two categories for each branch in the taxonomy -- do not branch for a single category
be sufficient content in each category to warrant existence
balance breadth & depth -- users must work harder to use a taxonomy three categories broad & nine deep than to use one that is seven wide and two deep
Hierarchical Taxonomy Design Issues
Hierarchical taxonomies should:
be balanced across each level of the taxonomy to provide users with a predictable experience
be offset with search functions
should never be displayed into flat structures
be reviewed periodically
Facet Taxonomies
Faceted taxonomy representedas a star data structure. Eachnode in the start structure isliked to the center focus. Any node can be linked to other nodes in other stars. Appears simple, but becomes complex quickly.
Type 3: Faceted Taxonomies
Resemble flat taxonomies when implemented, but have a different structure & purpose than flat taxonomies
There are no inherent relationships among categories in a faceted taxonomy – like a flat taxonomy
Resemble a star structure -- all facets pertain to the center object
All categories in a faceted taxonomy relate to a single object -- may describe a property or a value, different views or aspects of a single topic
Type 3: Faceted Taxonomies
An object may be:
electronic book -- each facet describes some aspect of the book - the author, the title, date of publication
facets describe the country’s population, geography, economic system, political system, history, …
Each facet may relate to facets in other taxonomies -- a faceted taxonomy describing a book may also have a link to a faceted taxonomy that describes a country
Metadata as Faceted TaxonomyThe primary implicit application of faceted taxonomies today & historically is as implicit metadata records
Traditionally, libraries have been the prime users or metadata
Today, portals and e-business systems are primary metadata users
Types of taxonomies that rely on metadata today:
IBM’s product & service catalog on the web
User interest profiles
Knowledge ‘push’ or syndication profiles
Selective dissemination of information or “push” profiles
Standards Based Metadata Schemes
Dublin Core Metadata Element - http://dublincore.org/dcregistry/index.html
GILS - Government Information Locator System - http://www.gils.net
VERS - Victorian Electronic Records Strategy -- http://www.prov.vic.gov.au/vers/welcome.htm
MARC - Machine Readable Cataloging - http://www.loc.gov/marc/marcdocz.html
UDDI - Universal Description, Discovery & Integration of Business – http://www.uddi.org
TEI -- Text Encoding Initiative - http://www.tei-c.org
ISAD(G) - International Standard Archival Description - www.ica.org/biblio/com/cds/isad_g_2e.pdf
Commercial Metadata Schemes
Ebay’s auction item descriptions - http://www.ebay.com
Amazon.com’s product descriptions - http://www.Amazon.com
Albertson’s product descriptions - http://www.albertsons.com/store/
Nordstrom’s product descriptions - http://www.nordstrom.com
Designing Faceted Taxonomies
Most important design issue for faceted taxonomy is that it be suited to its purpose -- that it contain the facets that are needed, & that their behavior is clear
Characteristics of each facet should be defined fully and distinctly -- while all facets pertain to a common object, each has a distinct behavior
Users should be able to manipulate facets distinctly -- it is important to define each facet exclusively, without overlap with other facets
Most faceted taxonomies are implicit structures - when they are made explicit, they are generally presented as record or table formats
Network Taxonomies
A network taxonomy is a plex data structure. Each node can have more than one parent. Any item in a plex structure can be linked to any other item. In plex structures, links can be meaningful & different.
Type 4: Network Taxonomies
Organizes content into both hierarchical and associative categories
May look like a computer network topology
Many relationships among categories or “nodes”
Relationships may have many different meanings
Category may have more than one higher level category
Any category in the taxonomy may be linked to any other category
Type 4: Network Taxonomies
Examples of network taxonomies:
Topic maps or ontologies
Thesauri -- !! A Thesaurus is NOT just a Hierarchy!!
Semantic networks
Implicit cross-walks for thesauri & controlled vocabularies from different knowledge domains
Implicit Network Taxonomies
Thesauri, concept maps & semantic networks can be explicit or implicit
Can be designed transparently into the knowledge management system as:
thesaurus facilitated search systems
recommender engines (...if you liked this, you might also like this)
vocabulary cross-walks from one source system to another
topic map cross-walks from one knowledge domain to another
Explicit Network Taxonomies
At one end of the scale we find simple, explicit network taxonomies such as topical taxonomies with See also references, or fully exposed thesauri
At the other enc of the scale, we find more complex, explicit network taxonomies such as visual concept maps or visual semantic networks. Consider the following example of network taxonomies accessible on the web:
World Bank Group’s Thesaurus – http://www2.multites.com/wb/
UMLS Semantic Network - http://www.nlm.nih.gov/research/umls/META3.HTML
Inxight’s Star Tree concept maps - http://eic.vestforsk.no/sitelense/eic.html
Designing Network Taxonomies
Structure you use to maintain the network taxonomy may not work well for display -- may have to break it into one or more types of taxonomies to implement it
Different kinds of relationships may be implemented in different ways - a single approach to display all types of relationships may not be effective
Three-dimensional presentations are well suited to network taxonomy implemented, but should be usability tested with users
Consider how the user will navigate a three-dimensional presentation
Try to maintain a consistent level of granularity of categories - avoid mixing pre-coordinated subject headings or broad classes with concepts
Conclusions
Every Information Professional’s ‘knowledge toolkit’ should contain a basic understanding of taxonomies & their suitability to different applications
Taxonomies are important building blocks in a full function information architecture
Knowledge of taxonomies will be a skill in increasing demand as the need to organize information grows
Need the organize information is growing exponentially, consistent with the amount of information produced, stored & disseminated