Classification in documentation is a tool for selection. It is essentially a 'finding system' for subject items... It is an artificial language, designed as a tool to aid in the selection of information from a store in response to search questions. The classification serves to standardise subject description, so that the description of a subject used by indexer and inquirer are more likely to coincide, thus maximising the probability of finding all items relevant to an inquiry.

The classification of subject matter may be carried out for all sort of special purposes - to arrange books on shelves, to group inventions in patents, to classify the raw materials, intermediates and products of importance to a particular manufacturer, and so on. All such arrangements have their particular uses and their particular problems.

I'm not a fan of classification. It is very difficult to come up with a classification scheme that's useful when what you're most interested in is things that don't fit in, things that you didn't expect. But some people decided that every page should carry classification. They came up with a scheme, based on page names, to establish a classification structure for a wiki. And these people who care about classification maintain it.

Classification in its simplest terms, means putting together things or ideas that are alike, and keeping separate those that are different.

In science there are uses many classifications of entities - plants, animals, rocks, soils, stars, diseases, occupations, and so on. In these taxonomies a classification must display genetic relations - for example, an evolutionary family tree of animal species - but its prime purpose is to aid in the identification of entities... Classification enables us to select, from the whole universe of known entities, the one that best matches one newly encountered.

Biological classifications have two major objectives: to serve as a basis of biological generalizations in all sort of comparative studies and to serve as a key to an information storage system... Is the classification that is soundest as a basis of generalizations also most convenient for information retrieval? This, indeed, seems to have been true in most cases I have encountered.

Scientific information is faced with the following problem. On the one hand, we have the world’s literature of science and technology, past and present, in many languages; on the other, and enquirer with a question. How to select, from a vast mass of words, the few that are the most closely relevant to an enquiry? It is this selection process that makes use of classification.

Classification is thought of by many librarians as either a fearful complication of a very simply act, or an outmoded, almost prehistoric, method of doing a very complex mathematical task.

The basic rules of classification are - Each characteristic of division must produce at least two classes - Only one principle of division must be used at a time, to produce mutually exclusive classes. - The species of any genius must be completely exhaustive of their parent class.

[Systems should be classified] on the basis of the types of inputs with which they must cope.

[A class category is] a collection of classes, some of which are visible to other class categories, and others of which are hidden.

What we call things and where we draw the line between one class of things and another depend upon the interests we have and the purposes of the classification. For example, animals are classified in one way by the meat industry, in a different way by the leather industry, in another different way by the fur industry, and in a still different way by the biologist. None of these classifications is any more final than any of the others; each of them is useful for its purpose.

Every way of classifying a thing is but a way of handling it for some particular purpose.

No one has ever devised a completely satisfactory classification scheme, and it seems unlikely that anyone ever will. This failing has always been apparent, but in recent years it has taken on increasingly urgent importance as scholarly literature has grown more complex and information retrieval more sophisticated. The library profession has long been aware of the difficulties created by the schemes available, but Foskett, librarian at the University of London's Institute of Education, has now examined the matter thoroughly in specific relation to the social sciences. He has written an immensely stimulating book, providing a perceptive critique of each of the existing classifications as well as new insight into possible solutions to the problems of classifying social science materials. He is very much in the Ranganathan camp and believes that the "facet analysis" which Ranganathan devised can conceivably supply the key to a much improved classification. He is especially taken with the more refined versions of this approach found in the work of the British Classification Research Group, ,and particularly in the work of Barbara Kyle. A schedule fashioned along these lines, he believes, would reveal subject. subdivisions and the relationships between subjects much more satisfactorily than any schedule used today. He would have a classification of such flexibility that any two concepts in the area of the social sciences could be related and this relation indicated in the notation of the material.