Indexing

In document management

In bibliography

The indexing of a Texte consists in locating in this one certain particularly significant words or expressions (called terms ) in a given context, and creating a bond between these terms and the original text. For example, the pages of index of a book take again (sometimes) the significant terms appearing in the book, and connect them to the pages of the book where these terms (or their synonyms) appears. This facilitates for the reader the localization of the pages or sections where a particular subject is mentioned. In the same way, the contents of a book is a form (enough coarse) of indexing.

To give a concrete example, this page-even of Wikipedia is indexed by the term “Indexing”, which undoubtedly allowed you to find it without reading before all the pages of “has” to “I”.

In addition, one can index objects which are not necessarily Texte: a catalog of museum indexes the objects of the museum, and could include/understand an index of terms connected to these objects.

Automatic indexing

The indexing can be manual (made by human), or automatic. The most effective method often for the use of linear Files is the indexing (it is also usable for the other types of Donnée S, stored in memory). The components are stored in the file in the order of their creation. One then uses a table of index, giving in first position the number of the component first, then second,… The advantage of this method is that the addition of components is optimal: one adds the value at the end of the file, one updates the table of index. Any displacement of a component will thus be replaced by a modification of the table of index, without real displacement of the value in the file. In general, this table can hold in memory, which allows a fast modification, in general one prefers to also save it on magnetic medium before leaving the program, which will avoid recreating it (for example to remake a sorting) with the next use. One can also use a list of index if displacements are frequent (but then the access becomes sequential). The second advantage of this method is that one can use several index simultaneously: for example for a list of people, one can create a index for the alphabetical classification of the names, another on the cities, one will thus reach more quickly all the indexed fields, whereas the not indexed fields must be satisfied of a sequential research, and this without modification in the file (a sorting by name then by city would have been necessary without indexing). On the other hand any modification will require the update of all the tables of index. The suppression, on the other hand, poses problem. In general, always to avoid the shifts in the files, one prefers to mark of a distinctive sign the removed fields (for example a nonalphabetical name or vacuum), then to update the index which will not point any more on this field. The retassage, enough length, are carried out only on order of the user or when it leaves the program. One can also (as in the method of the super-table) create a list of the empty fields, which will make it possible to reach it, more quickly than by a sequential research, during next insertion.

On a File indexed, one can again allow algorithms using insertion, since this one affects only the index (with rapid access). For sorting for example, one will be able to use sorting by insertion, with condition to optimize research of position of insertion (by dichotomy balanced for example), since this one requires readings of fields in the file whereas insertion involves only shifts in a table, one generally negligible duration in front of the time taken by research. One can also use a list of index rather than a table so necessary. (created by a Computer program), or with various intermediate grades “assisted” or semi-automatic (for example created by human assisted of a program proposing of the terms). The manual indexing of information is generally expensive: to correctly index a scientific text of a certain level, it is necessary to utilize people who are themselves able to include/understand the contents of the text, which imposes a considerable cost.

Although the indexing is based on relatively established techniques, there can be several indexings different from the same text, as valid the ones as the others, according to the use which must be made about it and of the public to which they are addressed. As example, imagine a text which is a description of gardens chosen in England; its indexing will be very different according to whether the public consists of gardeners, tourists, or geometricians.

Importance of the indexing of the electronic Documents

One of the major problems, in the economy of immaterial the, is the Exponential growth of the quantity of rough information, without for as much there existing really corresponding processes to allow a correct indexing of this information which would make it possible to draw the best party from it.

Associated terms: to index, index, Thesaurus, Key word, Synonymous synopsis,

In economy and finance

The indexing is the adjustment of a value on an index (index of Inflation, Market index) or a Reference rate.

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