The sequence of events for implementing the Lexicon will vary from institution to institution. Factors affecting this sequence include: the size of your collection, the diversity of your collection, the size of your staff, the level of training of your staff, whether object data has already been entered or not.

If you're buying ARGUS, you can get it with terms already loaded in the Lexicon. If you haven't started indexing (entering data in your Lexicon-controlled fields) yet, it's probably most efficient to load a set of terms into the Lexicon before you start. For a discussion on the merits of different sets of terms, see Mainstream Cataloguing Vocabulary Authorities?

Some of the other choices that need to be made are described in the following pages, and some suggestions are given on how the questions might be approached.

• Which fields should be Lexicon-controlled?
• What terms will be allowed in each field?
• Who will have control over what goes into the Lexicon?