Shelf Arrangement:

Once the library has a taken decision on the number of sequences in which the total collection is to be organised the material in the shelf in each sequence is arranged.

Alphabetical by Author/Title

In small libraries it may prove more helpful to arrange books by the alphabet in the name of the author or title. Generally books of fiction are arranged in a separate sequence by author of the book. Author arrangement in large libraries does not satisfy laws of library science.

Classified Arrangement:

As has already been noted, subject is the permanent and more useful basis for the arrangement of books. Size, title, sometimes even author may change from one edition to another edition of the book, but the subject remains basically unchanged. Hence books must be arranged systematically by subject if the goal of library service is to be achieved. Arrangement of books on shelves has to be
in accordance with the majority approaches to the documents. Approaches of the users to documents can be conveniently grouped as searching for known documents' and searching for unknown documents'. Documents whose existence is known to the user i.e., the user knows that there is a document written by such and such author/s, with such and such, a title, are called as known documents. When the user is not aware of the existence of the documents, such documents are called `unknown documents'. The categorisation known' and `unknown' are from the point of view of a user. 

Approaches to the known documents - which are relatively less, are usually through author title etc., and approaches to the unknown documents' is invariably the subject approach. Approaches to known documents are armed as Specific documents approach and approaches to the unknown documents' is termed as specific subject approach% The subject approach is the most predominant approach and thus a classified arrangement is very useful for the readers as they can find all the related materials at one place, browse through them and select the ones that they need. A systematic arrangement also leads them to the required materials. Block Arrangement This is the method of shelving books in a regular shelf to shelf, case to case order according to the classification scheme. In some busy public libraries a variant of this method is followed by having a rack of non-fiction books in between busy congested fiction racks. However, there is always the danger of mixing fiction and non-fiction books by the reader while browsing. 

Broken Order Arrangement

Libraries following the classified arrangement do not necessarily adhere strictly to the order of the chosen classification scheme. The common practice of breaking away from the order of the chosen classification, for various justifiable reasons, is known as the broken order. This practice leads to a more efficient shelf arrangement, due to the following reasons:

To shelve books, belonging to certain frequently used `classes' like fiction, at the beginning of the stacks.

To bring two thematically related but classificatory separated groups of books together, like 650 Management Science and 380 Commerce, or 400 Languages and 800 Literature. 

Accession Number: Arrangement by accession number could also be very effective in providing access. provided (a) that the stacks are closed and readers have no access to the stack, (b) there are a very detailed and in-depth subject and author catalogues providing access to content of the materials. (c) that the requests are for specific documents whose existence is known to the user. Since these conditions are difficult to fulfil, arrangement by accession number is not usually preferred.