How many terms are in AAT?
Thousands of AAT terms are added and edited every year. Currently the AAT contains around 34,000 records for concepts, including 131,000 terms, plus descriptions, bibliographic citations, and other information.
What are Scope Notes?
The Note or scope note clarifies the meaning and usage of a concept within the context of the AAT. A scope note differs from a definition in a dictionary or glossary in that, rather than providing all the possible meanings for a word, it identifies a single concept and explains its particular meaning. For example, a dictionary entry for barrel could include a dozen different definitions including those for a type of container, a firearm component, and a part of a musical instrument, all of which are barrels. In the AAT, barrels would appear three times, as barrels (aerophone components), barrels (containers), and barrels (firearm components); each is found in its appropriate part of the AAT hierarchical structure. In the AAT, words that are spelled the same but represent different concepts are homographs, and are recorded in separate records, unlike in a dictionary. The parenthetical qualifiers of the AAT allow users to distinguish among the homographs at a glance, but their scope notes further define them.
Scope notes serve two basic purposes: To clarify the precise meanings of concepts and to advise on usage. The following example for rhyta illustrates how a scope note clarifies meaning by precisely identifying a specific type of work and how it was used:
Example
Scope notes may describe the context of the concept, people or places relevant to the concept, and the time period during which it was evident, as in the example for Mannerist below.
Example
A scope note may describe different ways in which the terms may be used. It may alert the user if the meaning of a term has changed over time, as in the note for ale glasses below.
Example
Scope notes also guide users in selecting the most appropriate term among several possibilities. The choice may depend upon subtle differences in meaning among similar and closely related concepts, as in the note for naïve art below.
Example
What are the relationships in the AAT?
The defining characteristic of a thesaurus, that which distinguishes it from a flat list of terms such as a glossary, is the network of relationships among its terms and concepts. These relationships are semantic relationships, based on logical connections among the concepts, activities, and objects represented by the terms. Thesaurus construction standards identify three kinds of relationships, all of which are included in the AAT:
1. The Equivalence Relationship
Multiple terms may refer to the same concept. The relationship between terms that represent the same concept is the equivalence relationship. Among terms that refer to a single concept, one is chosen as the preferred term or descriptor. This is the term that is most often used to refer to the concept in scholarly or professional literature. Other terms for the concept may be synonyms, variant spellings, inverted forms of multi-word terms, different parts of speech for the same term, or terms in British English or other languages. In the traditional nomenclature of thesaurus construction, various terms in a record are labeled; in the AAT the terms include Descriptors, Alternate Descriptors, and Use For Terms.
Users of the AAT should decide whether or not it is important to their work to consistently use the same term for a given concept. Criteria for this decision should include whether or not the thesaurus is physically linked to their records in their cataloging system; if the thesaurus is not linked, it is generally advisable to use the same term each time reference it made to a given concept. Users who require such consistency may use either the descriptor or the alternate descriptor. Institutions typically use the alternate descriptor if they prefer the singular rather than the plural form of the term. The example below lists several terms that refer to the same concept. The descriptor is flagged with a "D," the alternate descriptor with "AD," and the use for terms with "UF."
Example
2. The Hierarchical Relationship
The hierarchical relationship links concepts to broader and narrower contexts. In the AAT, hierarchical relationships link generic classes of objects, actions, or concepts to their members or species. If a concept is a type of, kind of, example of, or manifestation of another concept, then a genus-species relationship exists. The relationships are expressed in displays by using indention. In the example below, chawls inherits all the characteristics of tenement houses, which inherits all the characteristics of apartment houses, which inherits everything belonging to multiple dwellings, which it inherits from dwellings. Ultimately, chawls is still a species of dwellings, albeit with many details and refinements of meaning added by the intervening types.
Example
The AAT is polyhierarchical, meaning that concepts may have multiple parents. For example, two concepts below are displaying with their non-preferred parent, indicated by an [N].
Example
3. The Associative Relationship
The associative relationships in AAT are cross-references, relationships, or links between terms that are not hierarchical or equivalent, as for the related concept in the record for Oseberg Style below.
Example
Why aren't the terms in the AAT organized in the way I expect to see them?
Within its given scope of art, architecture, and material culture, the AAT is organized for general use; it is not organized for one particular use or according to any specific discipline. For example, a user asked, why aren't communion cups and chalices narrower terms to church plate? This happens because church plate is a collective term for many different types and forms of objects used for ecclesiastical purposes, thus it is placed in the Object Genres hierarchy. Individual examples of church plate, such as communion cups and chalices or candlesticks, for instance, are found in various other places in the AAT, because the AAT's organization stresses function and form over the context in which an object is used. For this reason, communion cups and chalices are placed in Containers, and candlesticks in Furnishings, under lighting devices. However, the AAT links them to church plate as an alternate parent using polyhierarchical relationships.
Why are some of the terms that I need split into separate words and placed in separate hierarchies in the AAT?
The AAT is composed of terms that represent discrete concepts. This makes the thesaurus powerful and versatile; but it means that a term such as Baroque cathedrals will not be found in the AAT. This phrase must be constructed from separate AAT terms. Baroque is in the Styles and Periods hierarchy; cathedrals is in the Single Built Works hierarchy, under <churches by location or context>. When the two concepts are combined, they retain their individual meanings: They mean structures that are built in the Baroque style and serve as cathedrals (the seat of a bishop). However, every multiple-word concept is not necessarily split up in the AAT; some terms must be listed in the AAT as bound terms. An example is onion domes, in the Components hierarchy. Onion domes are bulbous domes, the style of which developed in Turkey and the Middle East. If the two words that make up onion domes are taken apart, they no longer mean the same thing (i.e., domes retains its meaning, but onions are pungent edible bulbs of Allium cepa).
Why and how do AAT records and terms change over time?
The AAT data changes with every year's publication, as has been true throughout its history. For example, see the old HN history notes in the old hardcopy publications of the AAT. If you open to any page of the published book, and there are dozens of changes noted, e.g., "April 1992 descriptor moved" or "March 1993 descriptor changed." Now such changes are tracked automatically in the Revision History, so it is possible for licensees to analyze changes in a more systematic way with each year's publication. In fact, when the data is available via APIs, they will be able to check changes regularly throughout the year.
AAT records are changed primarily for these reasons:
- To add new records (called "subjects" in the database) or to add new terms to existing subjects.
- To reflect changes in scholarship or usage of terms and their definitions.
- To make the data more consistent throughout. Given that the AAT has grown organically over time, legacy data and incoming contributed datasets occasionally require changes to existing records in order to maintain the logic and consistency of the whole.
- To correct legacy data where near-synonyms or upward postings were included in some records, whereas the editorial rules require only terms that are true synonyms be included in each subject. New subjects are created for the displaced terms; typically the near-synonyms are linked through associative relationships, and the upward postings are linked as parent/children.
- To institute the polyhierarchy, which was suppressed and misrepresented in legacy AAT data (when the database was monohierarchical, which was prior to 2001).
- To correct outright mistakes, either arising from contributed data or from editors' past mistakes.
The AAT has a very small staff. We rely upon the user community to grow the AAT, and we welcome users pointing out errors or inconsistencies.