CLASSIFICATION OF DOCUMENTS BY PHYSICAL CHARACTERISTICS:

Documents of various types have been classified  on the basis of their physical characteristics, familiarity and usage into four classes by Dr.S.R Ranganathan. On the other hand, C.W. Hanson  

The following is the schematic representation of the classification of documents as given by Ranganathan:

Ranganathan recognises the above four kinds of documents. Conventional documents are those which are usually recorded on paper in a natural language by writing, typing, printing  or some near-printing process. These are the most popular documents in use. These include books, periodicals, maps, atlases, etc. Neo- conventional documents are a new class of micro-documents, such as standards, specifications, patents, data, etc. Non-conventional documents  are a record in non-conventional size, shape or material. Audios, visuals, audio-visuals, microforms, etc. are included in this category. Meta-documents are a record of phenomena  made directly, unmediated, by the human mind. They are an instrument-record of natural and social phenomena made possible by instrument technology, photography, radar, etc. Ranganathan's classification groups documents in  the chronological order of their development and does not take into consideration the information characteristics of a 'document. He does not make any difference between an ordinary periodical and an indexing periodical. Also a book and a periodical belong to the same category according to him.