Controlled vocabularies

I've joined a study group! :) Well, two of us have decided to get together to study once a week so we can tackle this next assignment head on, and to help each other understand the concepts. Should be good. We had a sesh on Wednesday and talked through the answers to some of these questions which was helpful. I wasn't up to this module yet, which made it a little tricky, but we got there, and it made it easy to finish the module when I did get up to it today! :)

5.6 Exercise 2
1. Explain what is meant by specificity in indexing.
How precise the terms are – they need to be specific to that item. Not talking about the genre, but the example of the genre that is being indexed. A book about possums should be indexed under the heading possums rather than marsupials (Hider, p. 135).
2. Explain what is meant by co-extensive entry.
If there is more than one subject in the document, there needs to be headings for all of them, not one heading to summarise. So a book called ‘frogs and toads’ would have both frogs and toads as headings. A book about marsupials and mammals will require terms for both (Hider, p. 135).
3. They do it that way because the system was originally devised for card catalogues and hasn’t been changed. It is not appropriate for an online environment – it is unnecessary, and does not feel natural.
4. Free floating subdivisions – subdivisions that fit under many different headings, e.g. research would fit under library as well as business (and probably many others too). A subdivision is a qualifier under a heading to make it more specific (p. 138).
5. The main differences between thesauri and lists of subject headings:
Thesauri are used in defined subject fields (such as psychology or geology), whereas subject heading lists cover a wide range of subjects. Thesauri use specific terms, whereas subject heading lists usually use more general terms. Subject heading lists can have subdivided headings, unlike thesauri. Thesauri use single terms, so cannot use pre-coordinate searching, unlike subject heading lists. And Thesauri closely define the relationships among terms, whereas the subject heading lists do not always do so. (Hider & Harvey, p. 146.)
6. A scope note (SN) “indicates when to use the descriptor, defines scope” – it gives a definition of the descriptor so it is obvious when it is appropriate.

Module 5 - subject access

5.3 has thrown some questions my way:

Exercise 1 – Review questions

1. Explain the difference between derived indexing and assigned indexing.

Derived indexing involves using words that are within the resource itself for subject access; assigned indexing involves using words from a predermined list of vocabulary.

2. Explain the concept of exhaustivity.

Exhaustivity refers to the level of detail gone into when providing subject access. It refers to the number of terms selected to describe a resource, and how much information they cover - i.e. how much of a range of the information contained within the resource is indicated by its indexing terms.

3. Outline the main weaknesses associated with the use of a controlled vocabulary.

There is a potential for the terms to not be specific enough, as they have not been created or decided by the author and there may not be terms that directly match with the author's intended meaning. The terms are likely to be less exhaustive than natural language would be, as whoever is choosing them does not know the text as well as the author, and cost effectiveness may mean not much time is spent allocating terms. The terms may not be up to date either, so some important aspects may be missed. Finally, the searchers will need to know the language to search for the terms - they may need to learn these.

Controlled vocabularies

Still wrapping my mind around the idea of controlled vocabularies (I am possibly trying to make it more complicated than it needs to be), and when/how they are used, but I am pretty confident I can complete the activity below...

Activity

Locate the Art & Architecture Thesaurus (AAT) online. (Hint: either use a web search engine, or locate it from Michael Middleton’s Controlled vocabularies website.)

Assign terms from this thesaurus to:

1. a book about the architecture of castles
2. a journal article about sculptures of indigenous Australian animals

Using this Thesaurus, it was interesting to note the heirarchy display (by clicking on the symbol to the left of each result). From suggestions made in the forum, I am gathering that we need to be as specific as possible rather than including overarching terms. Because of this, there may only be one term... I think this is ok!

1.
- castles (fortifications)

2.
- constructions (sculpture)
- assemblages (sculpture)
- sculpture (visual work)
- statues

Ok that will do. This could be quite time consuming if you let it be. Also I have stared at the word sculpture for too long, and now it looks strange...