Syntax and Vocabulary of the Academic Metadata Format

maintained by Thomas Krichel

contains contributions hy José Manuel Barrueco Cruz, Christopher F. Baum, Tim D. Brody, Zhuoan Jiao, Ivan V. Kurmanov and Simeon M. Warner

draft: 2006–05–25

0. Status

This is a revision of the earlier AMF draft. This earlier draft is available in HTML, and in PDF format for US letter size paper and for A4 size paper.

This version is only available in HTML. It fixes errors in the description of the previous version and updates references to external developments. But it makes no substantive changes. It is written in XHTML 1.0 strict with machine-parsability in mind.

1. Introduction

This document is a draft for the Academic Metadata Format (AMF). AMF encodes descriptions of

• academics, i.e. people who produce scientific research;
• resources created and used by academics, at the moment these cover textual resources only but later non-textual resources like software and datasets may be added;
• organizations that are important in the academic world, including universities, research centers, academic publishers, scholarly societies, funding agencies etc.

AMF is not definite and may change at any moment. Despite the fact that it has been stable since early 2001, the current specification is provided as a basis for experimental deployment only. During this time, the draft standard's files are maintained at http://amf.openlib.org.

Work on the AMF has aimed to support the Open Archives Initiative by providing a richer metadata format than unqualified Dublin Core that is specialized in the scholarly communications area and that is directly usable with the OAI public metadata harvesting protocol. This implies two constraints on AMF.

• It has a simple XML syntax that does not make use of RDF.
• It is constrained through an XML Schema. The version that is constraind through an XML Schema version 1.0 is known as the "2001 version". Later versions may use a different

The remainder of the document is organized as follows. Section 2 introduces the general markup of AMF. Section 3 describes the names and semantics of elements used by AMF. Section 4 discusses constraints on the contents of elements. Such value constraints are indicated by the use of italics in the description of element semantics in Section 3. Section 5 presents presents optional attributes that may be useful to further qualify element contents. Section gives examples.

2. AMF markup

AMF is encoded in XML. All element names used by AMF use lowercase letters only.

The AMF data enclosed in an element that has the name amf. It is called the AMF root element.

AMF is an open vocabulary in the sense that the AMF XML schema allows to place elements from foreign vocabularies within the AMF vocabulary. This can be done on the root level of the AMF element, or in any child contents of that root element. Foreign element names must be namespace qualified.

If foreign vocabulary is used, then the AMF data must belong to the AMF namespace, the URI of which is http://amf.openlib.org. This may be achieved by specifying three attributes to the amf element. These are

• xmlns
  The value of this attribute must be the namespace URI for AMF: http://amf.openlib.org
• xmlns:xsi
  The value of this attribute must be the namespace URI for XML schema: http://www.w3.org/2001/XMLSchema-instance
• xsi:schemaLocation
The value of this attribute is a pair. The two elements of the pair are separated by whitespace.
• The first part is the namespace URI for AMF: http://amf.openlib.org
• The second part is the URI of the XML schema file for AMF: http://amf.openlib.org/2001/amf.xsd

If the <amf> element is the root element in an XML document, such a file can be called an AMF document.

Example:

<amf xmlns="http://amf.openlib.org"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://amf.openlib.org
                         http://amf.openlib.org/2001/amf.xsd">
 <text id="info:arXiv:hep-lat/0008015">
  <title>  ...
 </title>  ... 

 </text>
</amf>

In the example, text is a "noun" element. The AMF root element must contain one or more nouns. Nouns are repeatable. There are four nouns:

• person       a physical person
• organization an entity that has physical persons as its members
• text         a dctype:text
• collection   a dctype:collection of resources

Each instance of a noun element in AMF data that is not an empty element is called an AMF record. All child elements of AMF records are optional and repeatable. An AMF record admits two types of child elements.

• The first type are "adjective" elements. Adjectives give further information about nouns. Some adjectives have a nested structure. In the example above, title is an adjective.
• The second type are "verb" elements. Verbs relate one noun to other nouns. Each verb must have one or more nouns as children. It is good practice to place only on noun child element within each each verb. This is especially valuable if foreign vocabulary is used to quality the relation between the two nouns. Verbs must not have adjectives as direct children.

3. The elements of AMF

3.1. The person and organization nouns

The person noun element describes or refers to a physical person:.

 <person id="..."> ...adjectives and verbs... </person> or <person ref="..."/>

The organization noun element describes or refers to an organization. An organization is a group of two or more persons :.

 <organization id="..."> ...adjectives and verbs... </organization> or <organization ref="..."/>

Both nouns accept the same verbs and adjectives. Therefore they will be collectively referred to as the "p/o" noun in the remainder of this document.

3.1.1. The adjectives of the p/o noun

3.2.2: Text to person/organization verbs

3.2.3: Text to text verbs

3.2.4. Text to collection verbs

<ispartof> a text belongs to a collection, as dcq:isPartOf </ispartof>

3.3. The collection noun

The collection noun element is used whenever statements about a set of several texts are being made. This can be a classification collection, (i.e. all the texts that have the subject classification code), a serial, the papers presented at a conference etc.:

<collection id="..."> ...adjectives and verbs... </collection> or <collection ref="..."/>

3.3.1. The adjectives of the collection noun

<title> same as a journal title, conference title etc. </title>
<abbreviatedtitle> abbreviation, e.g. PRL </abbreviatedtitle>
<description> a plain text description of the collection, as dc:description </description>
<homepage> URL for humans to read more about the collection </homepage>
<accesspoint> URL for machines to access the collection </accesspoint>
<type> a collection type </type>
<identifier> an identifier for the collection from a scheme that doesnot use AMF, as dc:identifier </identifier>

3.3.2. Collection to collection verbs

<isreplacedby> as dcq:isReplacedBy </isreplacedby>
<replaces> as dcq:replaces </replaces>
<ispartof> as dcq:isPartOf </ispartof>
<haspart> as dcq:hasPart </haspart>

3.3.3. Collection to text verbs

<haspart> as dcq:haspart </haspart>

3.3.4. Collection to p/o verbs

<haseditor> </haseditor>
<haspublisher> in the sense of dc:publisher </haspublisher>
<hasmaintainer> p/o who maintain metadata about the collection </hasmaintainer>

4. Element value constraints

The values of some of the elements are restricted. These content types are listed here.

4.1. The date type

The date adjective is of the form yyyy[–mm[–dd]], where [] encloses optional components. For details, see the date type definition of XML Schema.

4.2. The URL type

The value must be a valid Uniform Resource Locator.

4.3. The email type

The value must be a valid email address.

4.4. The collection type type

The collection noun covers a wide variety of things in AMF. It is useful to indicate the type of a collection through a controlled vocabulary.

4.5: The text type type

The text noun covers a wide variety of things in AMF. It is useful to indicate the type of a text through a controlled vocabulary.

5 Attributes of elements

5.1. The id attribute

All AMF records (i.e. non-empty nouns) may have an id attribute. There are no value constraints for this attribute. If a value is set for a particular record, it is assumed that within the scope of a collection of AMF records, the record is uniquely identified by the value of this attribute.

A noun element that carries an id attribute can not carry a ref attribute.

5.2. The ref attribute

Any noun—be it empty or not—may carry a ref attribute. If it is present, its value is identical to the id attribute of another record. AMF ref attributes may be resolved to records that have the appropriate identifiers. The details of the resolution algorithm are outside the scope of AMF.

A noun element that carries an ref attribute can not carry a id attribute.

5.3. The from and until attributes

All verbs admit two additional attributes: from and until. The values of these attributes must be of the type date. These attributes indicate a time span for which the relationship holds. The dates are inclusive. Example:

<iseditorof from="1999-01-01" until="2000-01-01"> ... </iseditorof>

5.4. The xml:lang attribute

All adjective elements have an optional attribute called xml:lang. It takes the same syntax as in the XML 1.0 specification. It uses values for xml:lang from http://www.w3.org/TR/2000/WD-xml-2e-20000814#sec-lang-tag.

As a general rule, the xml:lang attribute refers to the value of the element content. For example <title xml:lang="fr"> Robin des Bois<title> does not mean that the text is a French translation of the adventures of Robin Hood.

There are natural exceptions to this rule. For example, if the lang attribute appears at an adjective that is constrained to contain a URL, it means that text that is found at the URL is written in that language.

5.5. The event attribute

All date elements may have an optional attribute event that indicates what happened on the date. The admissible values are

Example: <date event="created">2000-03</date>

5.6. The xsi:type attribute

The identifier, classification and keyword attributes may have an xsi:type attribute. In that case, controlled values for the value have been registered with AMF. The AMF Controlled vocabulary document lists all the controlled vocabularies.

6. Examples

None of the following examples is fictitious. However, the description of the items that is made through the examples may not be complete, to conserve space.

   
<amf>
 <text id="bible"> 
  <title id="Bible">The Holy Bible</title>
 </text>
 <text>
  <title>The book of Genesis</title>
  <ispartof>
   <text ref="bible"/>
  </ispartof>
 </text>
</amf>

<amf>
 <organization id="RePEc:edi:oecddfr">
  <name lang="en">Organization for Economic Development and Cooperation</name>
  <shortname lang="en">OECD</shortname>
  <name lang="fr">Organisation de Cooperation de Develloppement Economiques</name>
  <shortname lang="fr">OCDE</shortname>
  <homepage lang="en">http://www.oecd.org/</homepage>
  <homepage lang="fr">http://www.oecd.org/index-fr.htm</homepage>
  <haspart>
   <organization ref="RePEc:edi:edoecfr">
    <ispublisherof>
     <collection ref="RePEc:oed:oecdec">
      <haspart>
       <text>
        <hasauthor>
         <person ref="RePEc:per:1956-06-20:GIUSEPPE_NICOLETTI"/>
        </hasauthor>
        <title>
         REGULATION IN SERVICES: OECD PATTERNS AND ECONOMIC IMPLICATIONS
        </title>
        <abstract>
         The paper looks at patterns of regulation in service industries
         and explores their implications for service performance. 
        </abstract>
        <abstract lang="fr">
         Cette étude analyse les approches règlementaires dans les 
         secteurs des services et explore leurs implications pour 
         les performances sectorielles dans les pays de l'OCDE. 
        </abstract>
        <file>
         <url>http://www.olis.oecd.org/olis/2001doc.nsf/linkto/eco-wkp(2001)13</url>
         <format>application/pdf</format>
        </file>
       </text>
      </haspart>
     </collection>
    </ispublisherof>
   </organization>
  </haspart>
 </organization>
</amf>

<amf>
 <collection id="csfhrd">
  <title>Classification Scheme for Human Rights Documentation</title>
  <homepage>http://www.huridocs.org/clasengl.htm<homepage>
  <haseditor>
   <person> 
    <name>Ivana Caccia</name> 
    <email>icaccia@web.apc.org</email>
   </person>
  </haseditor>
  <haspart>
   <collection id="csfhrd:GEN II.10">
    <title>natural justice</title></collection>
   </collection>
   </haspart>
   <haspart>
    <collection id="csfhrd:GEN II.20">
     <title>universality / relativism</title>
    </collection>
   </haspart>
   <haspart>
    <collection id="csfhrd:GEN II.30">
     <title>philosophy & human rights </title>
    </collection>
   </haspart>
   <haspart>
    <collection id="csfhrd:GEN II.40">
     <title> political theories & human rights </title>
     <haspart>
      <collection id="csfhrd:GEN II.41">
       <title>democracy</title>
      </collection>
     </haspart>
     <haspart>
      <collection id="csfhrd:GEN II.42">
       <title>liberalism</title>
      </collection>
     </haspart>
     <haspart>
      <collection id="csfhrd:GEN II.45">
       <title>marxism</title>
      </collection>
     </haspart>
    </haspart>
   </collection>
  </haspart>
 </collection>
</amf>