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.