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Searching Materials Using Authority data: Web NDL Authorities Guide

1. What is Web NDL Authorities?

Web NDL Authorities is a service by the National Diet Library (NDL), Japan, to access authority data created and maintained by the NDL. As of the end of August 2022, approximately 1.39 million authority data are available through Web NDL Authorities.

Users can use authority data to identify authors and subjects, and search bibliographic data via the National Diet Library Online Search and Request Service ("NDL Online").


Figure 1: Search Box on the Top Page of Web NDL Authorities

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2. What is authority data?

Authority data organizes author's names and keywords that help users to search for materials. There are three types of authority data created by the NDL.

  • (1)Name Authority Data: Authority data for author's names or titles (personal names, family names, corporate body names, geographic names, works and uniform titles)
    e.g., "夏目漱石 (NATSUME, Soseki)", "岩波書店 (Iwanami Shoten)", "松山市 (Matsuyamashi)", "坊っちゃん (Bocchan)"
  • (2)Authority Data for Topical Term: Authority data for terms that are the theme of materials
    e.g., "個人主義 (Individualism)", "インターネット (Internet)"
  • (3)Authority Data for Genre/Form Term: Authority data for what a resource is
    e.g., "漫画 (Comics (Graphic works))", "児童図書 (Children's books)", "議会資料 (Legislative materials)", "LLブック (LL books)"

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3. How is the authority data useful? Search for materials using authority data

Creating a set of bibliographic data linked to any authority data enables users to precisely search materials without search noise (unintended search results), or search errors caused by inconsistency of search keywords (e.g., "ギリシャ" and "ギリシア").

The NDL provides a search service for materials using the function of authority data in Web NDL Authorities.

Sections 3.1. to 3.5. introduce how to search materials using the authority data in Web NDL Authorities for each situation. Section 3.6. explains the difference between the NDL Online's search screen and Web NDL Authorities.

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3.1. I want to find Shakespeare's works collectively

I want to find Shakespeare's works collectively, but the author's name is expressed differently from book to book, such as "シェークスピア", "Shakespeare", or "寒格斯比亜".

In such cases, please use Web NDL Authorities.

  • (1)Search "シェイクスピア (Shakespeare)" via the keyword search box
  • (2)Click the personal name authority data of "Shakespeare, William, 1564-1616" in the search result list → Go to the Detailed Information screen (When many search results are displayed, identify the individual you are looking for by referring to the birth/death dates presented next to the name, or the variant names recorded under the name)

    Figure 2: Search Result List Screen of "シェイクスピア (Shakespeare)"

    Figure 3: Detailed Information Screen of Personal Name Authority Data
    "Shakespeare, William, 1564-1616"
    The Variant Name(s) / Title(s) (in the green dotted box in Figure 3) on the Detailed Information screen shows various names for Shakespeare. The Variant Name(s) / Title(s) shows variations of names and titles, e.g., variant notations of names due to differences in language or alphabet of the authority file for personal names and corporate body names, as well as translated titles for the authority file for works. The authority data of Web NDL Authorities can also be searched from names or titles in Variant Name(s) / Title(s).
    For your information, the authority data may record not only different readings and spellings of names, but also information such as the year of birth/death of an individual and the date of establishment or termination of an organization. This enables users to distinguish different authors with the same surname/given name and different organizations with a same/similar name; thus, the data can be used to confirm a copyright protection period.
  • (3)Click the Author Link button → Search materials in the NDL Online
    In the Online Services at the NDL on the right side of the Detailed Information screen, there is a link button, which is linked to the NDL Online (in the yellow solid box in Figure 3). When a user clicks the link button, then the Search Result List screen of the bibliographic data, which is linked to the authority data, will be displayed.
    If a user clicks the Author Link button, then the user can search the works of Shakespeare collectively without concern for the variant notations of the author's name [Note 1]. Also, if a user clicks the Subject Link button, the user can search materials with the theme of Shakespeare. This function is explained in more detail in section 3.3.

    Figure 4: Example of Search Results of NDL Online via Author Link Button

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3.2. I want to find books written by 色川武大 (IROKAWA Takehiro) under variant names

IROKAWA Takehiro, a writer, apparently used a different pen name when writing mahjong novels. I want to find works written by his pen name for mahjong novels, not by 色川武大 collectively.

The NDL, as a general rule, creates each authority data for several names which one person in the modern era uses such as pen names, and mutually links them. Thus, users can confirm the relationships of each name and search for works by each name.

  • (1)Search "色川武大" via the keyword search box
  • (2)Click the personal name authority data of "色川, 武大, 1929-1989" from the search result list → Go to the Detailed Information screen

    Figure 5: Search Result List Screen of "色川武大 (IROKAWA Takehiro)"
    Under the heading "色川, 武大, 1929-1989" in the search result list, "→:阿佐田, 哲也, 1929-1989; 井上, 志摩夫, 1929-1989" is displayed, indicating the existence of Related Name(s) (Another Name) of "色川, 武大, 1929-1989".
  • (3)Click "阿佐田, 哲也, 1929-1989", the personal name authority data, displayed in the "Related Name(s) (Pseudonym)" of "色川, 武大, 1929-1989" → Go to the Detailed Information screen of "阿佐田, 哲也, 1929-1989"
    In the Detailed Information screen of "色川, 武大, 1929-1989", the links to the authority data of "阿佐田, 哲也, 1929-1989" and "井上, 志摩夫, 1929-1989" are displayed in the Related Name(s) (Pseudonym) (in the purple dashed line box (above) in Figure 6). On the other hand, in the Detailed Information screen of "阿佐田, 哲也, 1929-1989", the link to "色川, 武大, 1929-1989" is displayed as "Related Name(s) (Real Name) (in the purple dashed line box (below) in Figure 6). In this way, users can use Web NDL Authorities to refer to the individual authority data of multiple names owned by one person.
  • (4)Click the Author Link button in the Detailed Information screen of "阿佐田, 哲也, 1929-1989", the personal names authority data → Search materials in the NDL Online
    Users can distinguish books written by "阿佐田哲也" from books written by "色川武大" and search for them collectively with use of the NDL Online. Books such as "麻雀放浪記 (Mahjong Horoki)" are displayed; therefore, the pen name, under which 色川武大 wrote mahjong novels, seems to be 阿佐田哲也. For your information, the search result of "井上, 志摩夫, 1929-1989", the personal name authority data which is linked to "Related Name(s) (Pseudonym)", displays his historical novels.

    Figure 6: Search Result Comparison of "色川, 武大, 1929-1989" and "阿佐田, 哲也, 1929-1989"

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3.3. I want to find books about social networking services

I need to research and write a report on social networking. Should I look for books which include "SNS" in their titles? But there are many different social networking services.

When you want to find books about a certain theme, how do you search them? If you search via keywords in book titles only, you cannot find books which do not include the keywords in titles. In such cases, Web NDL Authorities enables users to search books on the theme which the user wants to find collectively and correctly regardless of each title.

  • (1)Search "SNS" via the keyword search box
  • (2)Click the Authority Data for Topical Term of ソーシャルネットワーキングサービス (Social networking service) in the search result list → Go to the Detailed Information screen

    Figure 7: Detailed Information Screen Showing Authority Data for
    Topical Term "ソーシャルネットワーキングサービス (Social networking service)"
  • (3)Click the Subject Link button → Search materials via the NDL Online
    Users can search books which include "ソーシャルネットワーキングサービス (Social networking service)" as a theme collectively via NDL Online [Note 2]. Books whose titles do not contain the words "SNS" or "ソーシャルネットワーキングサービス (Social networking service)" are also displayed in the search results, such as "LINE公式アカウント史上最強の成功テクニック".

    Figure 8: Example of Search Results in NDL Online via Subject Link Button
    The Detailed Information screen of Authority Data for Topical Term enables users to confirm relationships between authority data (Broader Term(s), Narrower Term(s), and Related Term(s)) (Purple dashed line box in Figure 7) and choose a more appropriate term from them. The relationships of each authority data will be displayed clearly by clicking the Graphical Display tab.

    Figure 9: Graphical Display of Authority Data for Topical Term
    "ソーシャルメディア (Social Media)"

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3.4. I want to search translated works of "星の王子さま (The Little Prince)" collectively

I want to read "星の王子さま (The Little Prince)". I would like to read it in my preferred translation, but I do not know how to find it.

A work of literature may be published with several different translated titles. It is hard to find all the translated titles and search one by one.
With the Authority File for Works, which was introduced by the NDL in January 2021, users can search books of the same work with variant titles collectively [Note 3]. "Work" is a concept that represents the idea of a work before it is expressed in written or spoken form. The NDL creates authority data for the following works.

  • Originals of reprinted, republished or translated (including modern and colloquial translations) classic works
  • Originals of modern works with multiple translated titles in Japanese

For details, please refer to "About Authority File for Works" (in Japanese) (link to Web NDL Authorities).

  • (1)Search "星の王子さま (The Little Prince)" via the keyword search box
  • (2)Choose the Authority File for Work "Le petit prince", the original title of "星の王子さま (The Little Prince)", in the search result list and click [Note 4] → Go to the Detailed Information screen

    Figure 10: Detailed Information Screen Showing Authority File for Work "Le petit prince"
    In the Detailed Information screen, the Variant Name(s) / Title(s) (the green dotted box in Figure 10), show various translated titles of "Le petit prince", known in Japan as "星の王子さま", such as "小さい王子" and "あのときの王子くん". Also, the link with the personal name authority data of Saint-Exupéry, Antoine de, 1900-1944, the author of "Le petit prince", is displayed in the Creator(s) (the blue double-line box in Figure 10).
  • (3)Click the Work Link button → Search materials via the NDL Online
    Regardless of the differences in translated titles, users can search for the work "Le petit prince" collectively. Also, books which were not written by Antoine Saint-Exupéry will not displayed in the search results, even if "星の王子さま" is included in the title. Academic books with the theme of 星の王子さま can be searched via the Subject Link button.

    Figure 11: Example of Search Results of NDL Online via Work Link Button

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3.5. I just want to find manga

I want to find manga (comics, graphic works) in general, regardless of the artist or title.

The "Genre/Form Term" enables users to find out what a material is (genre/form of the material), rather than what a material is about (the theme of the material). The NDL began applying four terms for books in January 2021, namely "漫画 (Comics (Graphic works))", "児童図書 (Children's books)", "議会資料 ( Legislative materials)" and "LLブック (LL books)", and has gradually expanded the terms and increased the kind of materials assigned terms [Note 5].

  • (1)Search "漫画 (Comics (Graphic works))" via the keyword search box
  • (2)Click the Authority Data for Genre/Form Term data of "漫画 (Comics (Graphic works))" in the search result list → Go to the Detailed Information screen

    Figure 12: Search Result List Screen of "漫画 (Comics (Graphic works))"

    Figure 13: Detailed Information Screen Showing Authority Data for
    Genre/Form Term of "漫画 (Comics (Graphic works))"
  • (3)Click the Genre Link button → Search the materials via the NDL Online
    Users can search manga regardless of each title, author, publisher, etc.

    Figure 14: Example of Search Results of NDL Online via Genre Link Button.
    If you want to search books with the theme of manga, please go to the detailed screen of the Authority Data for Topical Term "漫画 (Comic books, strips, etc.)" from the Search Result List screen and click the Subject Link button.

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3.6. How is it different from the NDL Online search screen?

This section explains the difference in searching between using the link button of Web NDL Authorities as described in 3.1. to 3.5. and typing a keyword directly into the search screen of NDL Online.

  • (1)Search via the link button of Web NDL Authorities
    With use of the link button of Web NDL Authorities to search NDL Online, users can search with the function for aggregating bibliographic data via the authority data.
    For example, if a user searches 河童 in NDL Online with the link button upon choosing Authority Data for Topical Term in Web NDL Authorities, books with the theme of 河童 as Japanese yokai (monster) such as "東北の河童昔話今昔"(Call number:KH22-L108) will be displayed. The bibliographic data shown as the search results are all linked to Authority Data for Topical Term "河童".
  • (2)Keyword search on NDL Online
    When a user types a keyword in the search screen of NDL Online, bibliographic data is searched via the letter string of the search keyword, without using the function for aggregating bibliographic data via the authority data.
    For example, if a user types "河童" in the "Subject" in the Advanced Search screen of the NDL Online, the letter string "河童" is searched regardless of whether it is linked to the authority data or not; therefore, "河童", the novel written by 芥川龍之介 (AKUTAGAWA Ryunosuke) and books with the theme of 妹尾河童 (SENOO Kappa), a stage artist, will be displayed.
    In the keyword search of the NDL Online for the bibliographic data which is linked to authority files for personal names and corporate body names, letter strings of Related Name(s) (Variant Name) of the linked authority files for personal names and corporate body names will also be searched. Therefore, if a user types "色川武大" in the field of Author/Editor in the NDL Online for search, works of 阿佐田哲也, and 井上志摩夫, which are pen names of 色川武大, will be displayed without distinguishing those names.

    Figure 15: Search Comparison of NDL Online and Web NDL Authorities
    The NDL Online has a function to search bibliographic data again via the magnifying glass icon (Search under the selected field on NDL Online) indicated next to the "Subject" and the "Author Heading" in the bibliographic records screen. For searching again, search via letter strings will be conducted the same as search via the search screen.
    If the bibliographic data in the bibliographic records screen is linked to the authority data, the arrow icon (link to the selected field on Web NDLA) is displayed next to "Subject" or "Author Heading". Users can confirm the authority data which links to Web NDL authorities by clicking the icon.
    In the case above, values of Name/Title in the authority data of Web NDL Authorities are displayed in "Subject" and "Author Heading".
    The function for searching the NDL Online again via the magnifying glass icon (Search under the selected field on NDL Online) searches bibliographic data based on the letter strings regardless of whether the data is linked to the authority data or not. Therefore, when a user searches the Author Heading "色川, 武大, 1929-1989" again, not only the bibliographic data which links to the personal name authority "色川, 武大, 1929-1989", but also the bibliographic data which links to Related Name(s) (Another Name) such as "阿佐田, 哲也, 1929-1989", "井上, 志摩夫, 1929-1989" will be displayed together as search results.

    Figure 16: Image of Search Result via Magnifying Glass Icon
    (Search under the selected field on NDL Online)

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4. Other functions: Utilization of authority data

With Web NDL Authorities, users can obtain authority data using functions such as downloading, RSS feed, and SPARQL Search in addition to searching materials. The obtained authority data can be imported into databases and applications [Note 6]. The section 4.4 below introduces an example which shows how to obtain authority data in Web NDL Authorities.

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4.1. Downloading authority data

Users can download authority data one by one at the form of the Detailed Information screen. The download formats include RDF/XML, RDF/Turtle, and JSON-LD.

Web NDL Authorities provides files for batch download for authority data which are within the scope of the National Diet Library Subject Headings (NDLSH) or the National Diet Library Genre/Form Terms (NDLGFT). The NDLSH are provided in RDF/XML or TSV formats, and the NDLGFT are provided in TSV format for downloading. For details, please refer to "Files for Batch Download" (link to Web NDL Authorities).

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4.2. RSS feed

Web NDL Authorities provides daily notifications of new entries, revised subject headings, and deletions of authority data which are within the scope of NDLSH. For details, please refer to "RSS Feed Notifications of New Subject Headings, etc." (link to Web NDL Authorities)

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4.3. SPARQL Search

Users can search and obtain data of Web NDL Authorities via the search NDL API (SPARQL and SPARQL 1.1 (trial version)) endpoints. Data formats include RDF/XML, RDF/Turtle, and JSON-LD. The maximum number of data that can be obtained at one time is 1,000 (for SPARQL 1.1 (trial version)). For details, please refer to "About SPARQL" and "SPARQL1.1 (trial version)" (in Japanese) (link to Web NDL Authorities).

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4.4. I want to find a subject heading that belongs to the classification NDC "596.7"

Our library has many books classified "596.7" (beverages) in the Nippon Decimal Classification (NDC). Users cannot separate coffee and alcohol books with the classification "596.7" only... I wonder what subject heading the NDL gives to books with the classification "596.7".

In such a case, please use Web NDL Authorities.

If a user selects the drop-down list of "NDC10" via the "by Classification" tab and searches "596.7" in the search box, the authority data with the representative classification numbers "596.7" in the NDC 10th edition will be displayed in the search result list. Users can download the authority data one by one from the Detailed Information screen.


Figure 17: Search Result List Screen of 596.7 (NDC10)

With use of SPARQL Search, a user can list obtained data easily and search with more complicated conditions.

The NDL provides forms to try SPARQL Search. For details such as the forms and API Specification for SPARQL Search, please refer to "About SPARQL" and "About SPARQL1.1 (trial version)" (in Japanese) (link to Web NDL Authorities).

For details of Web NDL Authorities' functions, please also refer to "Description of Functions" (link to Web NDL Authorities). Data provided via Web NDL Authorities can be used by anyone without application or charge. Please read the "Terms of Use" (link to Web NDL Authorities) before using Web NDL Authorities.

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[Note 1] The "Author Link button" search can be used for searching bibliographic data of publications in Japan and Japanese publications published abroad, excluding study books, pamphlets, etc. The "Author Link button" search can search part of non-Japanese books published abroad. The Japanese periodicals indexes and doctoral dissertations are not supported by the "Author Link button" search. For details on the standards of bibliographic data developed by the NDL, please refer to the "Standards of Bibliographic Data" (in Japanese).

[Note 2] In principle, "Subject Link button" search can be used for Japanese bibliographic data, excluding practical books, study books, pamphlets, etc. For details, please refer to the "Standards of Bibliographic Data" (in Japanese).

[Note 3] In principle, bibliographic data which are linked to the Authority File for Works and supported by the "Work Link button" search are those of Japanese books and foreign-language books published in Japan, and created after January 2021. The NDL is working to link the Authority Files for some well-known classical works to bibliographic data of Japanese/non-Japanese books created before December 2020.

[Note 4] The Name/Title of the Authority File for Works of classical works adopt Japanese titles regardless of the language of the original works, and contemporary works adopt titles in original languages in principle. However, Japanese titles will be adopted for contemporary works except for works written in other than Kanji, kana, Latin, Cyrillic, and Greek characters.

[Note 5] For the list of the Authority Data for Genre/Form Term compiled and maintained by the NDL and linked materials, please refer to the "National Diet Library Genre/Form Terms Cataloging Manual".

[Note 6] The following article introduces examples of the use of authority data provided by Web NDL Authorities.
KOREZUMI Kumiko, Efforts of Shishomarohan to LOD (Linked Open Data)―Examples of Use of Web NDL Authorities. The NDL Bibliographic Data Newsletter, No.3 in March 2015(serial no.34), p.1-3,
https://dl.ndl.go.jp/view/download/digidepo_9496832_po_2015_3.pdf?contentNo=1#page=2, (in Japanese) (Reference 2022-09-09)
Linked Web NDL Authorities and GeoNames.jp―Examples of Authority data. The NDL Bibliographic Data Newsletter, February 2017 (serial No.41), p.1-5,
https://dl.ndl.go.jp/view/download/digidepo_10358974_po_2017_2.pdf?contentNo=1#page=2, (in Japanese) (Reference 2022-09-09)

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