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Index: Library and information science

An index (plural: usually indexes, see below) is a list of words or phrases ('headings') and associated pointers ('locators') to where useful material relating to that heading can be found in a document. In a traditional back-of-the-book index the headings will include names of people, places and events, and concepts selected by a person as being relevant and of interest to a possible reader of the book. The pointers are typically page numbers, paragraph numbers or section numbers. In a library catalog the words are authors, titles, subject headings, etc., and the pointers are call numbers. Internet search engines, such as Google, and full text searching help provide access to information but are not as selective as an index, as they provide non-relevant links, and may miss relevant information if it is not phrased in exactly the way they expect.

색인이란 단어나 어귀 리스트이며, 그것의 헤딩을 문서에서 발견할 가능성과 관련해서 유익한 자료의 장소를 결합하도록 지시하는 포인터(위치지시자)를 포함하고 있다. 전통적인 책등색인에서, 헤딩은 저자의 이름, 장소, 그리고 사건, 그리고 어떤 사람에 의해 적절하다고 선택된, 그리고 그 책의 잠재적 독자에게 관심을 끌도록 하는 개념을 포함할 것이다. 포인터로는 전형적으로 페이지 번호, 문장 번호, 또는 장 번호가 사용된다. 도서관 목록에서 그것의 단어들은 저자, 서명, 주제명 표목 등이며 포인터들은 청구번호들이다. Google과 같은 인터넷 탐색엔진과 full text searching은 정보의 접근을 도와주지만, 색인처럼 선택적이지 않다. 왜냐하면 그것들이 기대하는 방식으로 정확하게 문장화되어 있지 않다면  그것들은 부적합한 링크를 제공할 뿐만 아니라 적합한 정보도 빠트리기 때문이다.

Purpose

Indexes are designed to help the reader find information quickly and easily. A complete and truly useful index is not simply a list of the words and phrases used in a publication (which is properly called a concordance), but an organized map of its contents, including cross-references, grouping of like concepts, and other useful intellectual analysis.

색인은 이용자가 정보를 빠르고 쉽게 찾는 것을 돕도록 디자인되었다. 완벽하고 참되고 유익한 색인은 단지 출판물에서 사용한 단어와 어귀의 리스트(이것은 용어색인이라 부르는 게 적합할 것이며)가 아니라,  그것의 콘텐트를 조직화한 지도이며, 그 속에는 상호참조, 유사개념의 집단화, 및 기타 유익한 지적 분석이 포함되어 있다.

Sample back-of-the-book index excerpt:

sage, 41-42. See also Herbs ← directing the reader to related terms

Scarlet Sages. See Salvia coccinea ← redirecting the reader to term used in the text

shade plants ← grouping term (may not appear in the text; may be generated by indexer)

hosta, 93 ← subentries

myrtle, 46

Solomon's seal, 14

sunflower, 47 ← regular entry

In books, indexes are usually placed near the end (this is commonly known as "BoB" or back-of-book indexing). They complement the table of contents by enabling access to information by specific subject, whereas contents listings enable access through broad divisions of the text arranged in the order they occur.

책에서 색인은 대체로 끝부분에 자리잡고 있다. 이것을 일반적으로 “BoB” 또는 “back-of-book” 색인이라 부른다. 이것은 특별한 주제에 의해 정보 접근을 가능하게 함으로써 목차를 보완하고 있다. 반면에 contents listings는 그것이 발생한 순서데로 배열된 텍스트의 광의적 분배를 거쳐서 접근하도록 한다.

It has been remarked that, while "[a]t first glance the driest part of the book, on closer inspection the index may provide both interest and amusement from time to time."

Index quality: 색인의 질

Some principles of good indexing include: 훌륭한 색인의 원칙;

1) Ensuring each topic/ section includes a variety of relevant index entries; use two

or three entries per topic.

각 주제/절은 여러 가지 적합한 색인 엔트리를 확실하게 포함하고 있어야 한다; 주제단 2~3개의 엔트리를 사용한다.

2) Understanding the audience and understand what kind of index entries they're

likely to look for.

사용자를 이해하고 어떤 종류의 색인 엔트리를 그들이 찾고자 할 것인가를 이해하라.

3) Use the same form throughout (singular vs. plural, capitalisation, etc.), using

standard indexing conventions.

표준 색인 규칙을 사용하여, 전체적으로 동일한 형태를 사용하라(단수 대 복수, 대문자,

등).

Indexing pitfalls: 함정

1) Significant topics with no index entries at all

2) Indexing 'mere mentions' --- "But John Major was no Winston Churchill..."

indexed under 'Churchill, Winston'

3) Circular cross-references: 'Felidae. See Cats' --- 'Cats. See Felidae'

4) References to discussions of a single topic scattered among several main

headings: 'Cats, 50-62' --- 'Felidae, 175-183'

5) Inconsistently indexing similar topics

6) Confusing similar names: Henry V of England, Henri V of France

7) Incorrect alphabetization: 'α-Linolenic acid' under 'A' instead of 'L'

8) Inappropriate inversions: 'processors, word' for 'word processors'

9) Inappropriate subheadings: 'processors: food, 213-6; word, 33-7'

10) Computer indexing from section headings: e.g. 'Getting to know your printer'

under 'G'

Indexer roles: 색인의 역할

Some indexers specialize in specific formats, such as scholarly books, microforms, web indexing (the application of a back-of-book-style index to a website or intranet), search engine indexing, database indexing (the application of a pre-defined controlled vocabulary such as MeSH to articles for inclusion in a database), and periodical indexing(indexing of newspapers, journals, magazines).

어떤 색인가는 학술도서, 마이크로자료, 웹 색인(웹 사이트나 인트라네트에 대한 권말색인형 색인의 어플), 탐색엔진 색인, 데이터베이스 색인(데이터베이스에 포함하기 위한 기사에 대하여 MeSH와 같이 미리 정의된 통제어휘의 어플)과 같은 특수한 포맷을 전문으로 다룬다.

Some indexers with expertise in controlled vocabularies also work as taxonomists and ontologists.

통제어휘에 전문가인 어떤 색인가는 또한 taxonomists 그리고 ontologists처럼 작업한다.

Some indexers specialize in particular subject areas, such as anthropology, business, computers, economics, education, government documents, history, law, mathematics, medicine, psychology, and technology. An indexer can be found for any subject.

어떤 색인가는 anthropology, business, computers, economics, education, government documents, history, law, mathematics, medicine, psychology, and technology과 같은 특별한 주제에 전문가이다. 색인가는 어떤 주제분야에서도 찾을 수 있다.

Standards: 표준

ISO 999:1996 Guidelines for the Content, Organization, and Presentation of Indexes.

# Back-of-the-book index

A back-of-the-book index (or just book index) is a collection of entries, often alphabetically arranged in an index, made to allow users to locate information in a given book (or related document).

책등색인 또는 그냥 책 색인은 색인 속에 자모순으로 배열된 기입항목의 집합체이며, 이것은 이용자로 하여금 특정한 책 또는 관련된 도큐멘트 속에 있는 정보의 위치를 찾도록 해준다.

Perhaps the most advanced investigation of problems related to book indexes is made in the development of topic maps, which started as a way of representing the knowledge structures inherent in traditional back-of-the-book indexes.

아마도 책 색인과 관련된 문제에서 가장 선도적으로 이루어진 조사는 전통적인 책등 색인과 밀접한 관계에 있는 지식 구조를 표현하는 방법에서 출발한 토픽 맵의 개발에서 이루어졌다.

1) A concordance is an alphabetical list of the principal words used in a book or body of work, with their immediate contexts. Because of the time, difficulty, and expense involved in creating a concordance in the pre-computer era, only works of special importance, such as the Vedas, Bible, Qur'an or the works of Shakespeare and other classical Latin and Greek authors, had concordances prepared for them.

A concordance is more than an index; additional material, such as commentary, definitions, and topical cross-indexing make producing them a labor-intensive process, even when assisted by computers.

Although an automatically generated index lacks the richness of a published concordance, the ability to combine the result of queries concerning multiple terms (such as searching for words near other words) has reduced interest in concordance publishing. In addition, mathematical technices such as Latent Semantic Indexing have been proposed as a means of automatically identifying linguistic information based on word context.

A bilingual concordance is a concordance based on aligned parallel text.

A topical concordance is a list of subjects that a book (usually The Bible) covers, with the immediate context of the coverage of those subjects. Unlike a traditional concordance, the indexed word does not have to appear in the verse. The most well known topical concordance is Nave's Topical Bible.

The first concordance, to the Vulgate Bible, was compiled by Hugh of St Cher (d.1262), who employed 500 monks to assist him. In 1448 Rabbi Mordecai Nathan completed a concordance to the Hebrew Bible. It took him ten years. 1599 saw a concordance to the Greek New Testament published by Henry Stephens and the Septuagint was done a couple of years later by Conrad Kircher in 1602. The first concordance to the English bible was published in 1550 by Mr Marbeck, according to Cruden it did not employ the verse numbers devised by Robert Stephens in 1545 but "the pretty large concordance" of Mr Cotton did. Then followed Cruden's Concordance and Strong's Concordance.

# Bibliographic index, a regularly updated print periodical publication that lists articles, books, and/or other information items,

A bibliographic index is a bibliography, an aid to search the literature of, for example, an academic field or discipline (example: Philosopher's Index), to works of a specific literary form (Biography Index) or published in a specific format (Newspaper Abstracts), or to the analyzed contents of a serial publication (New York Times Index).

서지 색인은 서지이며, 학술분야 문헌의 탐색(example: Philosopher's Index)을 위한, 특별한 문헌형태를 지닌 저작물(Biography Index)을 위한, 그리고 특별한 포맷(Newspaper Abstracts)으로 출판되거나 연속간행물(New York Times Index). 의 분석된 콘텐트에 대한 도구이다.

Indexes of this kind are issued in print periodical form (issued in monthly or quarterly paperback supplements, cumulated annually) or online (in which case they are called bibliographic databases). Citations are usually listed by author and subject in separate sections, or in a single alphabetical sequence under a system of authorized headings collectively known as controlled vocabulary, developed over time by the indexing service.

이런 종류의 색인은 인쇄물의 정기적 형태(월간, 계간, 연간)로 또는 온라인(어떤 경우에 그것들은 서지 데이터베이스라고 부른다)으로 발간된다. 인용색인은  색인 기관에서 오랫동안 개발한 통제어휘로 알려진 권위 있는 표목 시스템에 의해 독립적으로 나누거나 또는 단일 알파벳 순으로 저자와 주제를 리스트하는 것이 일반적이다.

"From many points of view an index is synonymous with a catalogue, the principles of analysis used being identical, but whereas an index entry merely locates a subject, a catalogue entry includes descriptive specification of a document concerned with the subject".

# Subject indexing, describing the content of a document by keywords.

Subject indexing is the act of describing or classifying a document by index terms or other symbols in order to indicate what the document is about, to summarize its content or to increase its findability. In other words, it is about identifying and describing the subject of documents. Indexes are constructed, separately, on three distinct levels: terms in a document such as a book; objects in a collection such as a library; and documents (such as books and articles) within a field of knowledge.

주제 색인작업이란 도큐멘트가 무엇에 관한 것인지를 나타내고, 그것의 콘텐트를 요약하거나 그것의 발견가능성을 높이기 위하여 색인어나 다른 부호를 사용하여 도큐멘트를 기술하거나 분류하는 행동이다. 다른 말로 해서, 이것은 도큐멘트의 주제를 규명하고 기술하는 것이다. 색인은 각각 별도의 3가지 차원으로 만들어진다: 책과 같은 도큐멘트에 들어 있는 terms, 도서관과 같은 장서에 들어있는 objects, 그리고 지식분야에 있는 책과 기사와 같은 documents.

Subject indexing is used in information retrieval especially to create bibliographic databases to retrieve documents on a particular subject. Examples of academic indexing services are Zentralblatt MATH, Chemical Abstracts and PubMed.

주제색인은 특별한 주제에 대한 도큐멘트를 검색하기 위한 서지 데이터베이스를 만들기 위한 정보검색분야에서 특히 사용된다. 학술색인기관의 예는 Zentralblatt MATH, Chemical Abstracts, PubMed 이다.

The index terms were mostly assigned by experts but author keywords are also common. The process of indexing begins with any analysis of the subject of the document. The indexer must then identify terms which appropriately identify the subject either by extracting words directly from the document or assigning words from a controlled vocabulary. The terms in the index are then presented in a systematic order.

색인어는 대부분이 전문가에 의해 할당되지만, 저자 키워드 또한 일반적으로 사용된다. 색인과정은 도큐멘트의 주제 분석에서 시작된다. 그런 다음에 색인가는 그 도큐멘트로부터 직접 단어를 발췌함으로써 또는 통제어휘로부터 단어를 할당함으로써 그 주제를 올바르게 나타내는 용어를 밝혀내야 한다. 색인에 들어 있는 용어들은 그런 다음에 체계적인 순서로 제시된다.

Indexers must decide how many terms to include and how specific the terms should be. Together this gives a depth of indexing.

색인가는 얼마나 많은 용어를 포함할 것인가 그리고 어떻게 그 용어를 특정화시킬 것인가를 결정해햐 한다. 이 2가지는 색인의 깊이를 결정한다.

Subject analysis

The first step in indexing is to decide on the subject matter of the document. In manual indexing, the indexer would consider the subject matter in terms of answer to a set of questions such as "Does the document deal with a specific product, condition or phenomenon?". As the analysis is influenced by the knowledge and experience of the indexer, it follows that two indexers may analyse the content differently and so come up with different index terms. This will impact on the success of retrieval.

색인의 첫 번째 단계는 그 도큐멘트의 주제를 결정하는 것이다. 수작업 색인에서, 색인가는 여러 가지 질문 - “그 도큐멘트가 특별한 결과, 조건, 또는 현상을 다루고 있는가? ”- 에 대한 답과 관련해서 주제를 고려할 수 있다. 분석은 색인가의 지식과 경험에 영향을 받으므로, 두 명의 색인가가 서로 다르게 그 콘텐트를 서로 다른 색인어를 가지고 분석하도록 하여야 한다. 이것은 성공적인 검색에 영향를 끼칠 것이다.

Automatic vs. manual subject analysis

Automatic indexing follows set processes of analysing frequencies of word patterns and comparing results to other documents in order to assign to subject categories. This requires no understanding of the material being indexed therefore leads to more uniform indexing but this is at the expense of the true meaning being interpreted. A computer program will not understand the meaning of statements and may therefore fail to assign some relevant terms or assign incorrectly. Human indexers focus their attention on certain parts of the document such as the title, abstract, summary and conclusions, as analysing the full text in depth is costly and time consuming. An automated system takes away the time limit and allows the entire document to be analysed, but also has the option to be directed to particular parts of the document.

Term selection

The second stage of indexing involves the translation of the subject analysis into a set of index terms. This can involve extracting from the document or assigning from a controlled vocabulary. With the ability to conduct a full text search widely available, many people have come to rely on their own expertise in conducting information searches and full text search has become very popular.

두 번째 단계는 주제분석을 색인어의 집합 속에서 해석하는 것이다. 여기에는 도큐멘트로부터의 발췌 또는 통제어휘의 할당이 포함된다. 전문 테스트 탐색을 폭넓게 사용할 수 있는 능력과 함께, 많은 사람들이 정보탐색을 수행하는데 자기 자신의 기술에 의존하게 됨으로써, 전문 텍스트 탐색이 매우 인기를 끌고 있다.

Subject indexing and its experts, professional indexers, catalogers, and librarians, remains crucial to information organization and retrieval. These experts understand controlled vocabularies and are able to find information that cannot be located by full text search. The cost of expert analysis to create subject indexing is not easily compared to the cost of hardware, software and labor to manufacture a comparable set of full-text, fully searchable materials. With new web applications that allow every user to annotate documents, social tagging has gained popularity especially in the Web.

One application of indexing, the book index, remains relatively unchanged despite the information revolution.

1) Extraction/Derived indexing

Extraction indexing involves taking words directly from the document. It uses natural language and lends itself well to automated techniques where word frequencies are calculated and those with a frequency over a pre-determined threshold are used as index terms.

발췌색인은 도큐멘트로부터 직접 단어를 취하는 것을 포함한다. 이것은 자연어를 사용하며, 단어빈도를 계산한 다음에 미리 정해진 임계치를 넘는 빈도를 가진 단어를 색인어로 사용하는 자동화 기법에서 널리 사용하고 있다.

A stop-list containing common words such as the, and would be referred to and such stop words would be excluded as index terms. Automated extraction indexing may lead to loss of meaning of terms by indexing single words as opposed to phrases. Although it is possible to extract commonly occurring phrases, it becomes more difficult if key concepts are inconsistently worded in phrases. Automated extraction indexing also has the problem that even with use of a stop-list to remove common words such as “the,” some frequent words may not be useful for allowing discrimination between documents. For example, the term glucose is likely to occur frequently in any document related to diabetes. Therefore use of this term would likely return most or all the documents in the database.

Post-co-ordinated indexing where terms are combined at the time of searching would reduce this effect but the onus would be on the searcher to link appropriate terms as opposed to the information professional. In addition terms that occur infrequently may be highly significant for example a new drug may be mentioned infrequently but the novelty of the subject makes any reference significant. One method for allowing rarer terms to be included and common words to be excluded by automated techniques would be a relative frequency approach where frequency of a word in a document is compared to frequency in the database as a whole.

Therefore a term that occurs more often in a document than might be expected based on the rest of the database could then be used as an index term, and terms that occur equally frequently throughout will be excluded. Another problem with automated extraction is that it does not recognise when a concept is discussed but is not identified in the text by an indexable keyword.

2) Assignment indexing

An alternative is assignment indexing where index terms are taken from a controlled vocabulary. This has the advantage of controlling for synonyms as the preferred term is indexed and synonyms or related terms direct the user to the preferred term. This means the user can find articles regardless of the specific term used by the author and saves the user from having to know and check all possible synonyms.

대안적인 것이 할당색인 이다. 이것은 색인러를 통제어휘로부터 취한다. 이것의 장점은 선호하는 용어를 색인함으로써 동의어를 통제할 수 있다는 것이고, 동의어나 관련어는 이용자가 선호하는 언어로 유도해 준다는 것이다. 이것이 의미하는 것은 이용자는 저자가 사용하는 특별한 용어와 상관없이 기사를 찾을 수 있으며 모든 잠재적인 동의어를 확인하고 알아야 하는 이용자의 부담을 덜어줄 수 있다는 것이다.

It also removes any confusion caused by homographs by inclusion of a qualifying term.

이것은 또한 용어의 질에 대한 것을 포함시킴으로써 동음이의어로 인해 발생하는 혼란을 제거할 수 있다.

A third advantage is that it allows the linking of related terms whether they are linked by hierarchy or association, e.g. an index entry for an oral medication may list other oral medications as related terms on the same level of the hierarchy but would also link to broader terms such as treatment.

세 번째 장점은 관련어의 링킹을 통하여 그것들이 계층적으로나 집합적으로 연결된다는 것이다.

Assignment indexing is used in manual indexing to improve inter-indexer consistency as different indexers will have a controlled set of terms to choose from. Controlled vocabularies do not completely remove inconsistencies as two indexers may still interpret the subject differently.

Index presentation

The final phase of indexing is to present the entries in a systematic order. This may involve linking entries. In a pre-coordinated index the indexer determines the order in which terms are linked in an entry by considering how a user may formulate their search.

색인화의 마지막 단계는 체계적인 순서로 항목들을 제시하는 것이다. 여기에는 링킹 항목도 포함될 수 있다. 전조합색인에서, 색인가는 이용자의 탐색방법을 고려하여  한 항목에 링크되는 용어들의 순서를 결정하여야 한다.

In a post-coordinated index, the entries are presented singly and the user can link the entries through searches, most commonly carried out by computer software. Post-coordination results in a loss of precision in comparison to pre-coordination.

후조합색인에서, 항목들은 한 개씩 제시되며, 이용자는 탐색을 통해 항목들을 연결시킬 수 있으며, 이 항목들 대부분은 일반적으로 컴퓨터 소프트웨어에 의해 전달된다. 결과적으로 후조합색인은 전조합색인과 비교하여 정확률이 떨어진다.

Depth of Indexing:

Indexers must make decisions about what entries should be included and how many entries an index should incorporate. The depth of indexing describes the thoroughness of the indexing process with reference to exhaustivity and specificity.

1) Exhaustivity

An exhaustive index is one which lists all possible index terms. Greater exhaustivity gives a higher recall, or more likelihood of all the relevant articles being retrieved, however, this occurs at the expense of precision. This means that the user may retrieve a larger number of irrelevant documents or documents which only deal with the subject in little depth.

망라적 색인은 모든 가능한 색인어를 전부 리스트하고 있는 색인이다. 망라성이 클수록 더 높은 재현율이 제공되거나, 검색되고 있는 모든 적절한 기사와의 유사성을 높인다. 그렇지만, 이것은 정확률을 희생시킨다. 이것이 의미하는 것은 이용자는 더 많은 수의 부적합한 도큐멘트 또는 깊이가 얕은 주제만을 다루고 있는 도큐멘트를 검색할 수도 있다는 것이다.

In a manual system a greater level of exhaustivity brings with it a greater cost as more man hours are required. The additional time taken in an automated system would be much less significant. At the other end of the scale, in a selective index only the most important aspects are covered.[9] Recall is reduced in a selective index as if an indexer does not include enough terms, a highly relevant article may be overlooked. Therefore indexers should strive for a balance and consider what the document may be used. They may also have to consider the implications of time and expense.

2) Specificity

The specificity describes how closely the index terms match the topics they represent. An index is said to be specific if the indexer uses parallel descriptors to the concept of the document and reflects the concepts precisely. Specificity tends to increase with exhaustivity as the more terms you include, the narrower those terms will be.

Indexing theory.

특수성은 색인어가 그것들잉 나타내는 주제와 얼마나 밀접한가를 나타내는 것이다. 만일 색인가가 도큐멘트의 개념을  위하여 병행 디스크립터를 사용하여 정확하게 그 개념을 반영한다면 그 색인은 특수하다고 말할 수 있다. 특수성은 여러분이 용어를 더 많이 포함시키면 시킬수록 그 용어들은 더욱 협소해 지는 것처럼 망라성과 같이 늘어나는 경향이 있다.

Hjørland (2011) found that theories of indexing is at the deepest level connected to different theories of knowledge:

1) Rationalist theories of indexing (such as Ranganathan's theory) suggest that subjects are constructed logically from a fundamental set of categories. The basic method of subject analysis is then "analytic-synthetic", to isolate a set of basic categories (=analysis) and then to construct the subject of any given document by combining those categories according to some rules (=synthesis).

2) Empiricist theories of indexing are based on selecting similar documents based on their properties, in particular by applying numerical statistical techniques.

3) Historicist and hermeneutical theories of indexing suggest that the subject of a given document is relative to a given discourse or domain, why the indexing should reflect the need of a particular discourse or domain. According to hermeneutics is a document always written and interpreted from particular horizon. The same is the case with systems of knowledge organization and with all users searching such systems. Any question put to such a system is put from a particular horizon. All those horizons may be more or less in consensus or in conflict. To index a document is to try to contribute to the retrieval of “relevant” documents by knowing about those different horizons.

4) Pragmatic and critical theories of indexing (such as Hjørland, 1997) is in agreement with the historicist point of view that subjects are relative to specific discourses but emphasizes that subject analysis should support given goals and values and should consider the consequences of indexing one way or another. These theories believe that indexing cannot be neutral and that it is a wrong goal to try to index in a neutral way. Indexing is an act (and computer based indexing is acting according to the programmers intentions). Acts serve human goals. Libraries and information services also serve human goals, why their indexing should be done in a way that supports these goals as much as possible. At a first glance this looks strange because the goals of libraries and information services is to identify any document or piece of information. Nonetheless is any specific way of indexing always supporting some kind of uses at the expense of other. The documents to be indexed intend to serve some specific purposes in a community. Basically the indexing should intend serving the same purposes. Primary and secondary documents and information services are parts of the same overall social system. In such a system different theories, epistemologies, worldviews etc. may be at play and users need to be able to orient themselves and to navigate among those different views. This calls for a mapping of the different epistemologies in the field and classification of the single document into such a map. Excellent examples of such different paradigms and their consequences for indexing and classification systems are provided in the domain of art by Ørom (2003) and in music by Abrahamsen (2003).

The core of indexing is, as stated by Rowley & Farrow to evaluate a papers contribution to knowledge and index it accordingly. Or, with the words of Hjørland (1992, 1997) to index its informative potentials.

"In order to achieve good consistent indexing, the indexer must have a thorough appreciation of the structure of the subject and the nature of the contribution that the document is making to the advancement of knowledge." (Rowley & Farrow, 2000, p. 99).

# Web indexing (or Internet indexing) refers to various methods for indexing the contents of a website or of the Internet as a whole. Individual websites or intranets may use a back-of-the-book index, while search engines usually use keywords and metadata to provide a more useful vocabulary for Internet or onsite searching. With the increase in the number of periodicals that have articles online, web indexing is also becoming important for periodical websites.

웹사이트나 인터넷의 콘텐트를 전반적으로 색인하는 다양한 방법을 말하며, 가각의 웹사이트나 인트라넷트는 책등색인을 이용하기도 하지만, 대체로 탐색엔진은 인터넷이나 온사이트 탐색을 위해 더 많은 유익한 어휘를 제공하도록 키워드와 메타데이터를 사용하고 있다. 온라인 기사를 포함하는 정기간행물의 수가 증가함에 따라, 웹색인은 정기간행물 웹사이트에서 중요하게 되었다.

1) Back-of-the-book-style web indexes may be called "web site A-Z indexes". The implication with "A-Z" is that there is an alphabetical browse view or interface. This interface differs from that of a browse through layers of hierarchical categories (also known as a taxonomy) which are not necessarily alphabetical, but are also found on some web sites. Although an A-Z index could be used to index multiple sites, rather than the multiple pages of a single site, this is unusual.

2)  Metadata web indexing involves assigning keywords or phrases to web pages or web sites within a meta-tag field, so that the web page or web site can be retrieved with a search engine that is customized to search the keywords field. This may or may not involve using keywords restricted to a controlled vocabulary list. This method is commonly used by search engine indexing.

# An abstracting service is a service that provides abstracts of publications, often on a subject or group of related subjects, usually on a subscription basis.

An indexing service is a service that assigns descriptors and other kinds of access points to documents.

The word indexing service is today mostly used for computer programs, but may also cover services providing back-of-the-book indexes, journal indexes, and related kinds of indexes.

An indexing and abstracting service is a service that provides shortening or summarizing of documents and assigning of descriptors for referencing documents.

The product is often an abstract journal or a bibliographic index, which may be a subject bibliography or a bibliographic database.