06 1420 DHenshaw Controlled Vocabulary

Controlled Vocabulary: 

Controlled Vocabulary Don Henshaw US Forest Service Research Corvallis, OR Andrews Forest LTER With materials from : John Porter (Virginia Coast LTER, Univ Virginia) Deanna Pennington (SEEK, Univ. New Mexico) Eric Landis (consultant, Natural Resource Information Management)

Keywords: 

Keywords Keyword = Key ideas/concepts expressed as words Keywording = The practice of selecting the most appropriate keywords to describe an object, image, or work.

Controlled Vocabulary: 

Controlled Vocabulary Groups different ways of describing a concept under a single word or phrase Makes a database easier to search Makes searching more efficient and precise Saves time of having to search under all of the synonyms for that term Requires consistency on the part of the individual indexing the database and the use of pre-determined terms.

Retrieval Performance Controlled vocabulary vs natural language systems: 

Retrieval Performance Controlled vocabulary vs natural language systems Free Text or Natural Language systems (e.g., Google search engine) often provide more results in a shorter time span because you are searching all the fields of a given database Free text searches work well for very specific searches, however, when a topic is older or broader in scope, you likely will retrieve irrelevant hits Free text searches may miss some records relevant to your search because the proper search term is not used Searching a database requires striking a balance between preciseness and generating enough hits to make the search successful

Thesaurus: 

Thesaurus A structured list of approved subject headings (also known as "preferred terms") that shows the relationships among those terms Relationships include broader/parent terms, narrower/child terms, and related terms Acts as a controlled vocabulary that specifies non-preferred terms (terms that should not be used for indexing or retrieval) and references the preferred concept that should be used instead Include term definitions, and/or scope notes that explain a particular context in which a term is being used

Slide6: 

Use of Keyword/Terms in the LTER Data Catalog and Bibliography

Common Methods to Achieve Semantic Clarification: 

Common Methods to Achieve Semantic Clarification Keywords - Assign keywords (often called annotating) to resources More efficient than searching through the entire text of the resource Generally uncontrolled and inconsistent Data dictionary - Provides a defined list of keywords (data dictionary) Clarifies what terms may be searched and what those terms explicitly mean Controlled vocabulary – Controls and limits terms that may be used Incorporates the use of synonyms for more efficient searches. Synonyms are terms that represent the same concept Thesaurus - allows synonyms and specifies the link between them, and in addition, shows other relationships, e.g., “related to” Searches return resources annotated to the search term Shows how terms are associated e.g. antonym Taxonomy - adds a classification hierarchy Relationships are “vertical” meaning they are limited to broader or narrower searches (e.g., parent-child relationships) Ontology – Encodes a conceptual model describing and defining the relationships among terms Allows searches by a term’s properties. Properties are the defining characteristics of each concept

Semantic Methods and CharacteristicsDeanna Pennington, LTER DataBits, Spring 2006: 

Semantic Methods and Characteristics Deanna Pennington, LTER DataBits, Spring 2006 Attribute

Semantic ClarificationDeanna Pennington, LTER DataBits, Spring 2006: 

Semantic Clarification Deanna Pennington, LTER DataBits, Spring 2006

Examples of other Resources: 

Examples of other Resources Global Change Master Directory http://gcmd.nasa.gov/ GEMET, the GEneral Multilingual Environmental Thesaurus http://www.eionet.europa.eu/gemet Idea is to use the best of the presently available excellent multilingual thesauri to define a core of general terminology for the environment WordNet http://wordnet.princeton.edu/ Knowledge Network for Biocomplexity (KNB) http://knb.ecoinformatics.org/index.jsp

Andrews LTER Theme Keywords: 

Andrews LTER Theme Keywords Controlled vocabulary of preferred keywords Provides primary basis for information search Developed locally by committee in time-consuming process Existing vocabularies considered too general I.e., Global Change Master Directory (GCMD) Lacks interoperability with other vocabularies Non-preferred keywords Provides mechanism to maintain legacy keywords Link provided to preferred keyword Hierarchic structure – 3 levels Improves search capability Imposes additional maintenance overhead

Andrews LTER Theme KeywordsTop-level keywords: 

Andrews LTER Theme Keywords Top-level keywords Habitat/Environment Aquatic/Riparian habitat, Estuarine habitat, Marine habitat, Terrestrial/Upland habitat Discipline/Approach Climate/Meteorology, Conservation biology, Data & Information management, Disturbance, Ecology, Genetics, Geology/geomorphology, History, Human dimension, Landscape ecology, Hydrology/Water, Invertebrates, Methods, Microbiota, Modeling, Plants, Program administration, Remote sensing, Resource management, Silviculture, Soils, Taxonomy/Systematics, Vertebrates Principle/Process Biological diversity, Biomass, Ecosystem processes, Physiological processes, Pollution, Population dynamics, Trophic relations

Andrews LTER Theme Keywords - Database Design: 

Andrews LTER Theme Keywords - Database Design Keyword_type Theme Keyword Temporal Keyword Stratum Keyword Taxonomic Keyword Methodology Keyword Catalog_type Database GIS database Image (planned)

Strategy to Implementation of a Controlled Vocabulary: 

Strategy to Implementation of a Controlled Vocabulary Goal: contribute to the credibility, usability, accessibility, and persistence of information products Considerations: Cost Sustainability Acceptability

Strategy to Implementation of a Controlled Vocabulary: 

Strategy to Implementation of a Controlled Vocabulary Options: Do nothing Establish taskforce or committee Adopt an existing vocabulary Adopt an existing vocabulary with modifications Build your own vocabulary Considerations: Cost, Sustainability, Acceptability