Text Annotation Techniques

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Text Annotation Techniques

• by Brian Wanner

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Annotated Text
Ordinary Text (Eg.) This is an ordinary text
document.
Annotated text (Eg.) lthtmlgt lttitlegt Sample
Document lt/titlegt ltbodygt This is an annotated
text document. lt/bodygt lt/htmlgt
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Document Type Definition (DTD)

• It is a specification that accompanies an
  annotated document.
• It aids the parser in identifying what the codes
  (or markup) are that separate paragraphs,
  identify topic headings
• It also indicates to the parser how each tag is
  to be processed.
• The DTD for every document is generally placed on
  top of the document.

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DTD Example

• This is an XML document with a Document Type
  Definition

lt?xml version"1.0"?gt lt!DOCTYPE note
lt!ELEMENT note (to,from,heading,body)gt
lt!ELEMENT to (PCDATA)gt lt!ELEMENT from
(PCDATA)gt lt!ELEMENT heading (PCDATA)gt
lt!ELEMENT body (PCDATA)gt gt
ltnotegt lttogtJoelt/togt ltfromgtJanelt/fromgt
ltheadinggtReminderlt/headinggt ltbodygtDon't forget
the homeworklt/bodygt lt/notegt
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Why use DTD?

• each file can carry a description of its own
  format with it.
• independent groups of people can agree to use a
  common DTD for interchanging data.
• Your application can use a standard DTD to verify
  that the data you receive from the outside world
  is valid.

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Standard Generalized Markup Language (SGML)

• SGML is a metalanguage
• a language for writing languages in.
• SGML is used to define the abstract structure of
  a DTD

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SGML

• Each markup language defined in SGML is called an
  SGML application. An SGML application is
  generally characterized by
• An SGML declaration.
• The SGML declaration specifies which characters
  and delimiters may appear in the application.
• A DTD
• A specification that describes the semantics to
  be ascribed to the markup. This specification
  also imposes syntax restrictions that cannot be
  expressed within the DTD.
• Document instances containing data (content) and
  markup. Each instance contains a reference to the
  DTD to be used to interpret it.

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HTML HyperText Markup Language XML eXtensible
Markup Language WML Wireless Markup
Language XHTML eXtensible HyperText Markup
Language SVG Scalable Vector Graphics SMIL
Synchronized Multimedia Integration Language
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• Seen from a DTD point of view, all XML documents
  (and HTML documents) are made up by the following
  simple building blocks
• Elements
• Tags
• Attributes
• Entities
• PCDATA
• CDATA

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Elements

• Elements are the main building blocks of both XML
  and HTML documents.
• Examples of HTML elements are "body" and "table".
  Examples of XML elements could be "note" and
  "message". Elements can contain text, other
  elements, or be empty. Examples of empty HTML
  elements are "hr", "br" and "img".

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Tags

• Tags are used to markup elements.
• A starting tag like ltelement_namegt marks up the
  beginning of an element, and an ending tag like
  lt/element_namegt  marks up the end of an element.
• Examples
• body element marked up with body tags
• ltbodygtbody text in betweenlt/bodygt.
• message element marked up with message tags
• ltmessagegtsome message in betweenlt/messagegt

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Attributes

• Attributes provide extra information about
  elements.
• Attributes are always placed inside the starting
  tag of an element. Attributes always come in
  name/value pairs. The following "img" element has
  additional information about a source file
• ltimg src"computer.gif" /gt
• The name of the element is "img". The name of the
  attribute is "src". The value of the attribute is
  "computer.gif". Since the element itself is empty
  it is closed by a " /".

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Entities

• Entities are variables used to define common
  text.
• Entity references are references to entities.

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PCDATA

• PCDATA means parsed character data.
• Think of character data as the text found between
  the start tag and the end tag of an XML element.
• PCDATA is text that will be parsed by a parser.
  Tags inside the text will be treated as markup
  and entities will be expanded. 

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CDATA

• CDATA also means character data.
• CDATA is text that will NOT be parsed by a
  parser. Tags inside the text will NOT be treated
  as markup and entities will not be expanded.

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What is HTML?

• HTML is a non-proprietary format based upon SGML,
  and can be created and processed by a wide range
  of tools, from simple plain text editors - you
  type it in from scratch- to sophisticated WYSIWYG
  authoring tools.

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HTML uses tags such as lth1gt and lt/h1gt to
structure text into headings, paragraphs, lists,
hypertext links etc.
Heading 1 Heading 2 Heading 3 Heading 4

• ltH1gtHeading 1lt/H1gt ltH2gtHeading 2lt/H2gt
  ltH3gtHeading 3lt/H3gt ltH4gtHeading 4lt/H4gt

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What is XML?

• Extensible Markup Language (XML) is a simple,
  very flexible text format derived from SGML.
• Originally designed to meet the challenges of
  large-scale electronic publishing, XML is also
  playing an increasingly important role in the
  exchange of a wide variety of data on the Web and
  elsewhere.

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XML Sample

• lt?xml version"1.0"?gt
• ltorder orderid"THX1138 customerNumber"3263827"gt
  
• ltlineitem itemid"C33"gt
• ltquantitygt36lt/quantitygt
• ltunitprice currency"dollars"gt.35lt/unitpricegt
• lt/lineitemgt
• ltlineitem itemid"M48"gt
• ltquantitygt1lt/quantitygt
• ltunitprice currency"dollars"gt2200lt/unitpricegt
• lt/lineitemgt
• lt/ordergt

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XML/HTML

• XML is not a replacement for HTML.XML and HTML
  were designed with different goals
• XML was designed to describe data and to focus on
  what data is.HTML was designed to display data
  and to focus on how data looks.
• HTML is about displaying information, XML is
  about describing information.

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XML/HTML

• The tags used to markup HTML documents and the
  structure of HTML documents are predefined. The
  author of HTML documents can only use tags that
  are defined in the HTML standard.
• XML allows the author to define his own tags and
  his own document structure.

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What is XHTML?

• The Extensible HyperText Markup Language (XHTML)
  is a family of current and future document types
  and modules that reproduce, subset, and extend
  HTML, reformulated in XML.
• XHTML Family document types are all XML-based,
  and ultimately are designed to work in
  conjunction with XML-based user agents.
• XHTML is the successor of HTML, and a series of
  specifications has been developed for XHTML.

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SMIL

• SMIL authoring offers a new way to assemble and
  deliver streaming multimedia presentations.
  Rather than the traditional way of creating a
  presentation by compiling a set of media into a
  single distributable file, SMIL lets authors
  choreograph separate media assets quickly and
  easily, with tools as simple as a text editor.
  Perhaps the best feature of SMIL is the ability
  to generate the code on-the-fly, as many Web
  pages are already created, and thereby offer
  personalized streaming multimedia.
• SMIL Demo
• SMIL Source

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SVG

• SVG is a language for describing two-dimensional
  graphics in XML
• SVG allows for three types of graphic objects
• vector graphic shapes (e.g., paths consisting of
  straight lines and curves)
• Images
• text

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SVG Sample

• ltsymbol id"whiteYellowBezier" overflow"visible"gt
  
• ltpath style"strokeblackfillnone" d"M 0,0 C
  0.25,-0.1 0.75,-0.1 1,0"gt
• ltanimate id"whiteYellowBezierAnim"
  attributeName"d" values"M 0,0 C 0.25,- 0.1
  0.75,-0.1 1,0 M 0,0 C25,-10 75,-10 100,0"
  dur"5s" repeatCount"3"/gt
• ltanimate attributeName"stroke-width"
  values"13" dur"5s" repeatCount"3" /gt
• ltanimate attributeName"stroke"
  values"whiteyellow" dur"5s" repeatCount"3" /gt
• lt/pathgt
• lt/symbolgt

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WML

• an annotation technique that allows the text
  portions of Web pages to be presented on cellular
  telephone and personal digital assistants
  (personal digital assistant) via wireless access.
• Though HTML can be used WML is used as it has
  lesser bandwidth resources.
• Also WML uses lesser power to process compared to
  HTML.

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Future Direction

• TEI (Text Encoding Initiative)
• an international project to develop guidelines
  for the preparation and interchange of electronic
  texts for scholarly research.
• Supported and promoted the use of SGML.

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• W3C (World Wide Web Consortium)
• Vision Contributions from several hundred
  dedicated researchers and engineers working for
  Member organizations, from the W3C Team , and
  from the entire Web community enable W3C to
  identify the technical requirements that must be
  satisfied if the Web is to be a truly universal
  information space.
• Design W3C designs Web technologies to realize
  this vision, taking into account existing
  technologies as well as those of the future.
• Standardization W3C contributes to efforts to
  standardize Web technologies by producing
  specifications (called "Recommendations") that
  describe the building blocks of the Web. W3C
  makes these Recommendations freely available to
  all.

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• Paper Critique