Glenda B. Claborne
ASSIGNMENT 3 - THESAURUS EVALUATION:
INVESTIGATING A CONTROLLED VOCABULARY
1.Type the name and the edition(if applicable) of the thesaurus you are using.
The Astronomy Thesaurus
Version 1.1 compiled for the International Astronomical Union, Commission 5
2.Describe and, as appropriate, give examples, for each of the following features of your thesaurus. If information is unavailable, or the feature is not applicable to the thesaurus, just tell me so. What I am looking for here is evidence that you understand what each of these features is.
a)source of terminology
The creators of the Astronomy Thesaurus used literary and user warrant in deciding what terms to include in the thesaurus. The use of literary warrant can be inferred from the statements in the introduction saying that “it is expected that most of the terminology used in current research will have been included” and that “the list of primary terms was initially selected from existing subject authority lists as well as from recognised reference texts in the field.” Although literary warrant was the initial source of terms for the thesaurus, it is also explained in the introduction to the thesaurus that “it has been supplemented and amended according to suggestions from a number of workers in various fields of astronomy during its evaluation in 1992.” This use of user warrant can be inferred further from another introductory statement which says that “the terms which have been selected reflect as far as possible ‘common usage’ by professional astronomers.”
b)specificity of terminology
The NT reference in the hierarchical relationships show how specific the terms are in the thesaurus. However, the lists of NTs
COSMOGONY
RELATIVITY
GENERAL THEORY OF RELATIVITY
SPECIAL THEORY OF RELATIVITY
c)semantic relationships
To show semantic relationships between terms, the thesaurus uses the following references:
1) For equivalence relationships, U:USE and UF: USE FOR are used as the inverse of the other to show similar meanings between words or phrases. A convention of lower case and upper case displays of primary terms is used to show equivalence between current and older terms. The primary term in a USE reference is in lower case but it directs users to a preferred term in upper case (e.g. for the primary term charged particles, one of the preferred terms following U is ELEMENTARY PARTICLES). The inverse is true when USE FOR is used (under the primary term ELEMENTARY PARTICLES following UF is charged particlesfor which the primary term is to be substituted). The user is advised to turn to the upper case term to find the hierarchical and associative relationships of the term with other terms.
2) For hierarchical relationships, BT: BROADER TERM is used to show which class or genus the term belongs to and NT: NARROWER TERM is used to show the sub-categories of the main term. For example, the primary term ELEMENTARY PARTICLES has the BT term PARTICLES and the NT terms ANTIPARTICLES,AXIONS, BARYONS, etc. The introduction to the thesaurus notes that the hierarchical relationships between terms in the thesaurus are strictly genus-species, not whole-part, relationships. It has the characteristic of hierarchical force as explained in the lecture.
3) For associative relationships, RT: RELATED TERM is used to direct a user to “a selection of other terms which are closely related or associated with the primary term but are not sub-categories of it. For example, using ELEMENTARY PARTICLES again as our primary term, we see that DARK MATTER, FEYNMAN DIAGRAMS, PARTICLE ACCELERATION, etc. are listed as RT terms under it. The introduction to the thesaurus notes that the list of RTs (and to a lesser extent the list of BTs and NTs) are by no means exhaustive and no attempt has been made to include all terms related to a primary term as a way of controlling the size of the thesaurus. See Also (SA) relationships are used as in See also ORBITAL ELEMENTS under the primary term ORBITS.
d)term definitions
In the opening web page to the thesaurus, there is a note that says, “this is a thesaurus, not a dictionary. You will not find definitions for the words within.” However, scope notes (SN) are used in the thesaurus for the following purposes (as noted in the introduction):
1) “To instruct in the use of a term for indexing and retrieval,” – many terms such as OPTIC, MEASUREMENT, MATHEMATICS and SKY have the scope note “Combine with other terms;”
2) “To define and to limit use,” – for example, the term WEAK INTERACTIONS has the note “Between atomic particles” to define and limit its use to only between atomic particles and not, for example, between planetary bodies.
3) “To explain a principle of division (different meanings for the same word),” – for example, OPTICAL WINDOWS as referring to Low absorption in atmosphere and OPTICAL WINDOWS [OPTICS] to denote the meaning of the term in the context of optics.
Other examples of scope notes that I have come across in the thesaurus include Primary optics of telescopes for the term OBJECTIVES and Polishing optics to accurate shape for FIGURING. Both these notes help in differentiating the meaning of the terms as used in astronomy and as used in common parlance.
In addition to scope notes, the semantic relationships as described in item c) provide a rich context from which to infer term definitions (we can infer the definition of a term from knowing which class or genus it belongs to or which terms it is equivalent to). Furthermore, the use of lower case terms as alternative terms to use for older publications or data gives added context to term definitions.
e)term syntax and semantics
The introduction notes that the American National Standards Institute (ANSI) standard No Z39 (1980) was used to construct the thesaurus so I infer that this standard determined to a large degree the ordering of words in the terms included in the thesaurus. The introduction notes some rules used with regards to hyphens and the possessive ‘s’, both of which determine the order of words in a term since they usually assume adjectival forms and almost always precede the noun. Hyphens are not used but are replaced by a space in case of such terms as HERBIG-HARO OBJECTS or are not replaced by a space in the case of prefixes as in SEMIREGULAR VARIABLES. The possessive ‘s’ is not used – GOULD BELT instead of GOULD’S BELT, or in the case of laws, constants, and theories, the name is used as an adjective instead like in HUBBLE LAW. The introduction specifically notes that the ANSI standard for plurals has been used for nouns so that count nouns should normally be expressed as plurals and noncount (mass) nouns as singular. Some of the term semantics have been addressed in my answer to item d) on term definitions, I think.
f)pre-coordination vs. post-coordination of terms
Most of the terms included in the thesaurus are ones in which only a single concept exists so we may say that in general, the Astronomy Thesaurus is a post-coordinate vocabulary. It was noted in the introduction that “pre-coordination has been kept to a minimum in the expectation that Boolean logic will be used to form search statements for most of the subcategories.” Terms consisting of multiple concepts (pre-coordinate) can be created using terminology that has been placed in the Appendices as noted in the introduction. The terms in the Appendices are considered part of the thesaurus and are expected to be combined with other terms using Boolean operators. There are a several pre-coordinate terms included in the main thesaurus using the preposition “of” like LOCAL GROUP OF GALAXIES, LOCAL STANDARD OF REST, GENERAL THEORY OF RELATIVITY,VELOCITY OF LIGHT, ZONE OF TOTALITY, CLUSTERS OF GALAXIES, GENERAL THEORY OF RELATIVITY.
g)creation of terms: synthetic vs. enumerative
I would say that the creation of terms for The Astronomy Thesaurus is largely enumerative though the mention of terms placed in the Appendices which could best be “synthesized’ using the Boolean ‘AND’ confused me there for a minute. The individual terms are enumerated in the Appendices and indexers can create new terms by combining them using the Boolean ‘AND’ as in the examples given in the introduction like LITHIUM AND ABUNDANCE to create LITHIUM ABUNDANCE. But is this new term created by indexers to be included back into the thesaurus or used for indexing only? If the latter, then the new term does not really describe the process of synthesis for term creation for the thesaurus. I have to admit that I still confuse synthesis of terms for search use either to include in an index or to retrieve information from databases with synthesis of terms for inclusion into the CV itself. I guess synthesis occurs if the new terms created are included in the thesaurus but this doesn’t seem likely because the terms from which they are created are listed in the Appendices for the purpose of controlling the size of the thesaurus. Furthermore, the creation of the terms was done through the software LEXICON. There was mention of instructing the software to create hierarchical relationships and hierarchical displays but no mention of tables containing single terms with rules to follow in combining the single terms from different tables to create a new term. The citation order of words appears to be in natural word order rather than in inverted order.
h)scope of the thesaurus
In the introduction, it was explained that “the authors have included those terms which are clearly related to astronomy but they have not included all aspects in broader subjects such as history, instrumentation, electronics, computing, physics, rocketry and space research.”
i)other noteworthy features
I think a noteworthy feature of The Astronomy Thesaurus is a provision for language support in the form of the A Multi-Lingual Supplement toThe Astronomy ThesaurusVersion 2.0: January 1995. The introduction to this multi-lingual supplement states that it is “designed to be used in conjunction with the full English thesaurus in order to obtain meaning and context for the terminology.” It was created with the recognition that the use of literary warrant effectively limited the sources of terminology to those main journals in astronomy which happen to be published mostly in English. The creation of the multi-lingual supplement was intended to account for current and historical literature in astronomy in all countries. The authors believe that the multi-lingual supplement “will assist the astronomical community (scientists and librarians) with the use of terminology in the major languages of science - English, French, German, Italian and Spanish.”