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Happy World Standards Day 2017!

Forum Standaardisatie - 11 oktober 2017 - 5:30pm
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Event date zaterdag, oktober 14, 2017

Happy World Standards Day 2017!

 

 

Plasterk bekijkt verhalen schade ICT-fiasco

Digitaal bestuur - 11 oktober 2017 - 5:03pm
Minister Ronald Plasterk (Binnenlandse Zaken) laat onderzoeken of de schade van het ICT-fiasco met de modernisering van de zogeheten Basisregistratie Personen (BRP) misschien toch is te verhalen. Hij heeft dat woensdag toegezegd na aandringen van …

DXC Technology verwerft Logicalis SMC

Computable - 11 oktober 2017 - 2:30pm
Het Amerikaanse ict-concern DXC Technology neemt ict-dienstverlener Logicalis SMC uit Rijswijk over van de Britse ict-dienstverlener Logicalis Group. De Nederlandse tak, opgericht in 1998, telt 184 medewerkers in Nederland en in het Verenigd Koninkrijk. Logicalis SMC...
Categorieën: ICT , Informatievoorziening

Grote zorgen over complexe IT Omgevingswet

Digitaal bestuur - 11 oktober 2017 - 2:24pm
Bureau ICT-toetsing (BIT) maakt zich zorgen over de ontwikkeling van het digitale stelsel van de Omgevingswet en adviseert het huidige programma flink te reduceren omdat het te complex is. Ter illustratie van de complexiteit: er moeten nu naar schatting …

Het veelbelovende huwelijk tussen ai en bi

Computable - 11 oktober 2017 - 2:03pm
Zowel artificiële intelligentie (ai) ofwel kunstmatige intelligentie (ki) als business intelligence (bi) bestaan al enige tijd. Al die tijd leefden ze apart van elkaar. Maar nu zien we de convergentie van deze concepten, vooral door de...
Categorieën: ICT , Informatievoorziening

Het veelbelovende huwelijk tussen ai en bi

Computable - 11 oktober 2017 - 2:03pm
Zowel artificiële intelligentie (ai) ofwel kunstmatige intelligentie (ki) als business intelligence (bi) bestaan al enige tijd. Al die tijd leefden ze apart van elkaar. Maar nu zien we de convergentie van deze concepten, vooral door de...
Categorieën: ICT , Informatievoorziening

KVAN/BRAIN over rapport kortere overbrengstermijn

Het bestuur van KVAN/BRAIN heeft in een brief aan de minister van OCW laten weten voorstander te zijn van een drastische verkorting van de overbrengingstermijn. OCW liet de impact van een dergelijke maatregel onderzoeken naar aanleiding van de motie Segers, volgend op de affaire rond 'het bonnetje van Teeven'. KVAN/BRAIN benadrukt in reactie op het onderzoeksrapport dat alleen een kortere overbrengingstermijn niet voldoende is om de Archiefwet aan te passen aan de digitale tijd en eisen van transparantie. KVAN/BRAIN breken met het oog daarop een lans voor de Wet Open Overheid, die nu voorligt in de Eerste Kamer. Invoering van de WOO in combinatie met een aanzienlijk kortere overbrengingstermijn zou een grote impuls zijn voor verbetering van de kwaliteit van de overheidsinformatievoorziening.

Reinwardt Academie zoekt stageplaatsen

De stageperiode van de tweedejaarsstudenten loopt van 29 januari tot en met 11 mei 2018. Naast de werkzaamheden voor de instelling, krijgt de student vanuit de opleiding opdrachten op het gebied van publieksonderzoek, organisatiekunde, en erfgoedtheorie. Hiermee laten wij de student vanuit een professionele invalshoek kijken naar de beroepspraktijk. Er is gekozen voor een geïntegreerde aanpak tussen werken en leren. De student verricht circa 30 uur per week werkzaamheden voor uw organisatie en besteedt ongeveer 10 uur per week aan opdrachten vanuit de academie. Lees meer in het document Informatie tweedejaarsstage bachelor Cultureel erfgoed. Voor vragen kunt u contact opnemen met stagecoördinator Mirjam Wijnands via rwa-stagebureau@ahk.nl. Meer info op de website van de Reinwardt Academie.

Open brief: Stoppen BRP houdt ict-monopolie in stand

Computable - 11 oktober 2017 - 12:30pm
Geachte Leden van de Tweede Kamer der Staten-Generaal, vandaag gaat u, waarschijnlijk voor de laatste keer, in debat met de (demissionaire) minister van Binnenlandse Zaken en Koninkrijksrelaties (BZK) over het beantwoorden van 110 Kamervragen over de...
Categorieën: ICT , Informatievoorziening

Plasterks’ BRP getruukte zwanenzang

Computable - 11 oktober 2017 - 11:55am
Vandaag om 15.00 uur debatteert de Commissie Binnenlandse Zaken over de antwoorden die vertrekkend minister Ronald Plasterk heeft gegeven op een spervuur van Kamervragen. We zien weer de uitsteltactiek die de minister al sinds 2013 hanteert,...
Categorieën: ICT , Informatievoorziening

Dell Technologies start IoT-divisie

Computable - 11 oktober 2017 - 11:50am
Dell Technologies kondigt een nieuwe internet of things-divisie aan. Deze is gespecialiseerd in IoT-oplossingen en introduceert nieuwe producten, een bijbehorend partnerprogramma en consumptiemodellen. De divisie is een onderdeel van Dell zijn nieuwe internet of things-strategie, waarbij...
Categorieën: ICT , Informatievoorziening

CGI bouwt virtueel spoorwegnet voor Prorail

Computable - 11 oktober 2017 - 11:31am
It-dienstverlener CGI heeft het Nederlandse spoorwegnet nagebouwd in een voor Prorail gecreëerde 3D-wereld. Hierbinnen kunnen lvc-simulaties plaatsvinden (‘live virtual constructive’), waarin de werkelijke situatie en een virtuele, gesimuleerde wereld samenkomen. Een en ander wordt gerealiseerd in...
Categorieën: ICT , Informatievoorziening

Structural Metadata: Key to Structured Content

Story Needle - 11 oktober 2017 - 11:27am

Structural metadata is the most misunderstood form of metadata.  It is widely ignored, even among those who work with metadata. When it is discussed, it gets confused with other things.  Even people who understand structural metadata correctly don’t always appreciate its full potential. That’s unfortunate, because structural metadata can make content more powerful. This post takes a deep dive into what structural metadata is, what it does, and how it is changing.

Why should you care about structural metadata? The immediate, self-interested answer is that structural metadata facilitates content reuse, taking content that’s already created to deliver new content. Content reuse is nice for publishers, but it isn’t a big deal for audiences.  Audiences don’t care how hard it is for the publisher to create their content. Audiences want content that matches their needs precisely, and that’s easy to use.  Structural metadata can help with that too.

Structural metadata matches content with the needs of audiences. Content delivery can evolve beyond creating many variations of content — the current preoccupation of many publishers. Publishers can use structural metadata to deliver more interactive content experiences.  Structural metadata will be pivotal in the development of multimodal content, allowing new forms of interaction, such as voice interaction.  Well-described chunks of content are like well-described buttons, sliders and other forms of interactive web elements.  The only difference is that they are more interesting.  They have something to say.

Some of the following material will assume background knowledge about metadata.  If you need more context, consult my very approachable book, Metadata Basics for Web Content.

What is Structural Metadata?

Structural metadata is data about the structure of content.  In some ways it is not mysterious at all.  Every time you write a paragraph, and enclose it within a
<p> paragraph element, you’ve created some structural metadata.  But structural metadata entails far more than basic HTML tagging.  It gives data to machines on how to deliver the content to audiences. When structural metadata is considered as a fancy name for HTML tagging, much of its potency gets missed.

The concept of structural metadata originated in the library and records management field around 20 years ago. To understand where structural metadata is heading, it pays to look at how it has been defined already.

In 1996, a metadata initiative known as the Warwick Framework first identified structural metadata as “data defining the logical components of complex or compound objects and how to access those components.”

In 2001, a group of archivists, who need to keep track of the relationships between different items of content, came up with a succinct definition:  “Structural metadata can be thought of as the glue that binds compound objects together.”

By 2004, the National Information Standards Organization (NISO) was talking about structural metadata in their standards.  According to their definition in the z39.18 standard, “Structural metadata explain the relationship between parts of multipart objects and enhance internal navigation. Such metadata include a table of contents or list of figures and tables.”

Louis Rosenfeld and Peter Morville introduced the concept of structural metadata to the web community in their popular book, Information Architecture for the World Wide Web — the “Polar Bear” book. Rosenfeld and Morville use the structural metadata concept as a prompt to define the information architecture of a websites:

“Describe the information hierarchy of this object. Is there a title? Are there discrete sections or chunks of content? Might users want to independently access these chunks?”

A big theme of all these definitions is the value of breaking content into parts.  The bigger the content, the more it needs breaking down.  The structural metadata for a book relates to its components: the table of contents, the chapters, parts, index and so on.  It helps us understand what kinds of material is within the book, to access specific sections of the book, even if it doesn’t tell us all the specific things the book discusses.  This is important information, which surprisingly, wasn’t captured when Google undertook their massive book digitization initiative a number of years ago.  When the books were scanned, entire books became one big file, like a PDF.   To find a specific figure or table within book on Google books requires searching or scrolling to navigate through the book.

Image of Google Books webpage.The contents of scanned books in Google Books lack structural metadata, limiting the value of the content.

Navigation is an important purpose of structural metadata: to access specific content, such as a specific book chapter.  But structural metadata has an even more important purpose than making big content more manageable.  It can unbundle the content, so that the content doesn’t need to stay together. People don’t want to start with the whole book and then navigate through it to get to a small part in which they are interested. They want only that part.

In his recent book Metadata, Richard Gartner touches on a more current role for structural metadata: “it defines structures that bring together simpler components into something larger that has meaning to a user.” He adds that such information “builds links between small pieces of data to assemble them into a more complex object.”

In web content, structural metadata plays an important role assembling content. When content is unbundled, it can be  rebundled in various ways.  Structural metadata identifies the components within content types.  It indicates role of the content, such as whether the content is an introduction or a summary.

Structural metadata plays a different role today than it did in the past, when the assumption was that there was one fixed piece of large content that would be broken into smaller parts, identified by structural metadata.  Today, we may compose many larger content items, leveraging structural metadata, from smaller parts.

The idea of assembling content from smaller parts has been promoted in particular by DITA evangelists such as Anne Rockley (DITA is a widely used framework for technical documentation). Rockley uses the phrase “semantic structures” to refer to structural metadata, which she says “enable(s) us to understand ‘what’ types of content are contained within the documents and other content types we create.”  Rockley’s discussion helpfully makes reference to content types, which some other definitions don’t explicitly mention.  She also introduces another concept with a similar sounding name, “semantically rich” content, to refer to a different kind of metadata: descriptive metadata.  In XML (which is used to represent DITA), the term semantic is used generically for any element. Yet the difference between structural and descriptive metadata is significant — though it is often obscured, especially in the XML syntax.

Curiously, semantic web developments haven’t focused much on structural metadata for content (though I see a few indications that this is starting to change).  Never assume that when someone talks about making content semantic, they are talking about adding structural metadata.

Don’t Confuse Structural and Descriptive Metadata

When information professionals refer to metadata, most often they are talking about descriptive metadata concerning people, places, things, and events.  Descriptive metadata indicates the key information included within the content.  It typically describes the subject matter of the content, and is sometimes detailed and extensive.  It helps one discover what the content is about, prior to viewing the content.  Traditionally, descriptive metadata was about creating an external index — a proxy — such as assigning a keywords or subject headings about the content. Over the past 20 years, descriptive metadata has evolved to describing the body of the content in detail, noting entities and their properties.

Richard Gartner refers to descriptive metadata as “finding metadata”: it locates content that contains some specific information.  In modern web technology, it means finding values for a specific field (or property).  These values are part of the content, rather than separate from it.  For example, find smartphones with dual SIMs that are under $400.  The  attributes of SIM capacity and price are descriptive metadata related to the content describing the smartphones.

Structural metadata indicates how people and machines can use the content.  If people see a link indicating a slideshow, they have an expectation of how such content will behave, and will decide if that’s the sort of content they are interested in.  If a machine sees that the content is a table, it uses that knowledge to format the content appropriately on a smartphone, so that all the columns are visible.  Machines rely extensively on structural metadata when stitching together different content components into a larger content item.

diagram showing relationship of structural and descriptive metadataStructural and descriptive metadata can be indicated in the same HTML tag.  This tag indicates the start of an introductory section discussing Albert Einstein.

Structural metadata sometimes is confused with descriptive metadata because many people use vague terms such as “structure” and “semantics” when discussing content. Some people erroneously believe that structuring content makes the content “semantic”.  Part of this confusion derives from having an XML-orientation toward content.  XML tags content with angle-bracketed elements. But XML elements can be either structures such as sections, or they can be descriptions such as names.  Unlike HTML, where elements signify content structure while descriptions are indicated in attributes, the XML syntax creates a monster hierarchical tree, where content with all kinds of roles are nested within elements.  The motley, unpredictable use of elements in XML is a major reason it is unpopular with developers, who have trouble seeing what role different parts of the content have.

The buzzword “semantically structured content” is particularly unhelpful, as it conflates two different ideas together: semantics, or what content means, with structure, or how content fits together.  The semantics of the content is indicated by descriptive metadata, while the structure of the content is indicated by structural metadata.  Descriptive metadata can focus on a small detail in the content, such as a name or concept (e.g., here’s a mention of the Federal Reserve Board chair in this article).  Structural metadata, in contrast, generally focuses on a bigger chunk of content: here’s a table, here’s a sidebar.   To assemble content, machines need to distinguish what the specific content means, from what the structure of the content means.

Interest in content modeling has grown recently, spurred by the desire to reuse content in different contexts. Unfortunately, most content models I’ve seen don’t address metadata at all; they just assume that the content can pieced together.  The models almost never distinguish between the properties of different entities (descriptive metadata), and the properties of different content types (structural metadata). This can lead to confusion.  For example, a place has an address, and that address can be used in many kinds of content.  You may have specific content types dedicated to discussing places (perhaps tourist destinations) and want to include address information.  Alternatively, you may need to include the address information in content types that are focused on other purposes, such as a membership list.  Unless you make a clear distinction in the content model between what’s descriptive metadata about entities, and what’s structural metadata about content types, many people will be inclined to think there is a one-to-one correspondence between entities and content types, for example, all addresses belong the the content type discussing tourist destinations.

Structural metadata isn’t merely a technical issue to hand off to a developer.  Everyone on a content team who is involved with defining what content gets delivered to audiences, needs to jointly define what structural metadata to include in the content.

Three More Reasons Structural Metadata Gets Ignored…

Content strategists have inherited frameworks for working with metadata from librarians, database experts and developers. None of those roles involves creating content, and their perspective of content is an external one, rather than an internal one. These hand-me-down concepts don’t fit the needs of online content creators and publishers very well.  It’s important not to be misled by legacy ideas about structural metadata that were developed by people who aren’t content creators and publishers.  Structural metadata gets sidelined when people fail to focus on the value that content parts can contribute in difference scenarios.

Reason 1: Focus on Whole Object Metadata

Librarians have given little attention to structural metadata, because they’ve been most concerned with cataloging and  locating things that have well defined boundaries, such as books and articles (and most recently, webpages).  Discussion of structural metadata in library science literature is sparse compared with discussions of descriptive and administrative metadata.

Until recently, structural metadata has focused on identifying parts within a whole.  Metadata specialists assumed that a complete content item existed (a book or document), and that structural metadata would be used to locate parts within the content.  Specifying structural metadata was part of cataloging existing materials. But given the availability of free text searching and more recently natural language processing, many developers question the necessity of adding metadata to sub-divide a document. Coding structural metadata seemed like a luxury, and got ignored.

In today’s web, content exists as fragments that can be assembled in various ways.  A document or other content type is a virtual construct, awaiting components. The structural metadata forms part of the plan for how the content can fit together. It’s important to define the pieces first.

Reason 2: Confusion with Metadata Schemas

I’ve recently seen several cases where content strategists and others mix up the concept of structural metadata, with the concept of metadata structure, better known as metadata schemas.  At first I thought this confusion was simply the result of similar sounding terms.  But I’ve come to realize that some database experts refer to structural metadata in a different way than it is being used by librarians, information architects, and content engineers.  Some content strategists seem to have picked up this alternative meaning, and repeat it.

Compared to semi-structured web content, databases are highly regular in structure.  They are composed of tables of rows and columns.  The first column of a row typically identifies what the values relate to.  Some database admins refer to those keys or properties as the structure of the data, or the structural metadata.  For example, the OECD, the international statistical organization, says: “Structural metadata refers to metadata that act as identifiers and descriptors of the data.  Structural metadata are needed to identify, use, and process data matrixes and data cubes.”   What is actually being referred to is the schema of the data table.

Database architects develop many custom schemas to organize their data in tables.  Those schemas are very different from the standards-based structural metadata used in content.  Database tables provide little guidance on how content should be structured.  Content teams shouldn’t rely on a database expert to guide them on how to structure their content.

Reason 3: Treated as Ordinary Code

Web content management systems are essentially big databases built in programming language like PHP or .Net.  There’s a proclivity among developers to treat chunks of content as custom variables.  As one developer noted when discussing WordPress: “In WordPress (WP), the meaning of Metadata is a bit fuzzier.  It stores post metadata such as custom fields and additional metadata added via plugins.”

As I’ve noted elsewhere, many IT systems that manage content ignore web metadata metadata standards, resulting in silos of content that can’t work together. It’s not acceptable to define chunks of content as custom variables. The purpose of structural metadata is to allow different chunks of content to connect with each other.  CMSs need to rely on web standards for their structural metadata.

Current Practices for Structural Metadata

For machines to piece together content components into a coherent whole, they need to know the standards for the structural metadata.

Until recently, structural metadata has been indicated only during the prepublication phase, an internal operation where standards were less important.  Structural metadata was marked up in XML together with other kinds of metadata, and transformed into HTML or PDF.  Yet a study in the journal Semantic Web last year noted: “Unfortunately, the number of distinct vocabularies adopted by publishers to describe these requirements is quite large, expressed in bespoke document type definitions (DTDs). There is thus a need to integrate these different languages into a single, unifying framework that may be used for all content.”

XML continues to be used in many situations.  But a recent trend has been to adopt more light weight approaches, using HTML, to publish content directly.  Bypassing XML is often simpler, though the plainness of HTML creates some issues as well.

As Jeff Eaton has noted, getting specific about the structure of content using HTML elements is not always easy:

“We have workhorse elements like ul, div, and span; precision tools like cite, table, and figure; and new HTML5 container elements like section, aside, and nav. But unless our content is really as simple as an unattributed block quote or a floated image, we still need layers of nested elements and CSS classes to capture what we really mean.”

Because HTML elements are not very specific, publishers often don’t know how to represent structural metadata within HTML.  We can learn from the experience of publishers who have used XML to indicate structure, and who are adapting their structures to HTML.

Scientific research, and technical documentation are two genres where content structure is well-established, and structural metadata is mature.  Both these genres have explored how to indicate the structure of their content in HTML.

Scientific research papers are a distinct content type that follows a regular pattern. The National Library of Medicine’s Journal Article Tag Suite (JATS) formalizes the research paper structure into a content type as an XML schema.  It provides a mixture of structural and descriptive metadata tags that are used to publish biomedical and other scientific research.  The structure might look like:

<sec sec-type="intro"> <sec sec-type="materials|methods"> <sec sec-type="results"> <sec sec-type="discussion"> <sec sec-type="conclusions"> <sec sec-type="supplementary-material" ... >

Scholarly HTML is an initiative to translate the typical sections of a research paper into common HTML.  It uses HTML elements, and supplements them with typeof attributes to indicate more specifically the role of each section.  Here’s an example of some attribute values in their namespace, noted by the prefix “sa”:

<section typeof="sa:MaterialsAndMethods"> <section typeof="sa:Results"> <section typeof="sa:Conclusion"> <section typeof="sa:Acknowledgements"> <section typeof="sa:ReferenceList">

As we can see, these sections overlap with the JATS, since both are describing similar content structures.  The Scholarly HTML initiative is still under development, and it could eventually become a part of the schema.org effort.

DITA — the technical documentation architecture mentioned earlier — is a structural metadata framework that embeds some descriptive metadata.  DITA structures topics, which can be different information types: Task, Concept, Reference, Glossary Entry, or Troubleshooting, for example.  Each type is broken into structural elements, such as title, short description, prolog, body, and related links.  DITA is defined in XML, and uses many idiosyncratic tags.

HDITA is a draft syntax to express DITA in HTML.  It converts DITA-specific elements into HTML attributes, using the custom data-* attribute.  For example a “key definition” element <keydef> becomes an attribute within an HTML element, e.g. <div data-hd-class="keydef”>
.  Types are expressed with the attribute data-hd-type.

The use of the data-* offers some advantages, such as javascript access by clients.  It is not, however, intended for use as a cross-publisher metadata standard. The W3C notes: “A custom data attribute is an attribute in no namespace…intended to store custom data private to the page or application.”  It adds:

“These attributes are not intended for use by software that is not known to the administrators of the site that uses the attributes. For generic extensions that are to be used by multiple independent tools, either this specification should be extended to provide the feature explicitly, or a technology like microdata should be used (with a standardized vocabulary).”

The HDITA drafting committee appears to use “hd” in the data attribute to signify that the attribute is specific to HDITA.  But they have not declared a namespace for these attributes (the XML namespace for DITA is xmlns:ditaarch.)  This will prevent automatic machine discovery of the metadata by Google or other parties.

The Future of Structural Metadata

Most recently, several initiatives have explored possibilities for extending structural metadata in HTML.  These revolve around three distinct approaches:

  1. Formalizing structural metadata as properties
  2. Using WAI-ARIA to indicate structure
  3. Combining class attributes with other metadata schemas
New Vocabularies for Structures

The web standards community is starting to show more interest in structural metadata.  Earlier this year, the W3C released the Web Annotation Vocabulary.  It provides properties to indicate comments about content.  Comments are an important structure in web content that are used in many genres and scenarios. Imagine that readers may be highlighting passages of text. For such annotations to be captured, there must be a way to indicate what part of the text is being referenced.  The annotation vocabulary can reference specific HTML elements and even CSS selectors within a body of text.

Outside of the W3C, a European academic group has developed the Document Components Ontology (DoCO), “a general-purpose structured vocabulary of document elements.”  It is a detailed set of properties for describing common structural features of text content.  The DoCO vocabulary can be used by anyone, though its initial adoption will likely be limited to research-oriented publishers.  However, many specialized vocabularies such as this one have become extensions to schema.org.  If DoCO were in some form adsorbed by schema.org, its usage would increase dramatically.

Diagram showing document ontologyDiagram showing document components ontology  WAI-ARIA

WAI-ARIA is commonly thought of as a means to make functionality accessible.  However, it should be considered more broadly as a means to enhance the functionality of web content overall, since it helps web agents understand the intentions of the content. WAI-ARIA can indicate many dynamic content structures, such as alerts, feeds, marquees, and regions.

The new Digital Publishing WAI-ARIA developed out of the ePub standards, which have a richer set of structural metadata than is available in standard HTML5.  The goal of the Digital Publishing WAI-ARIA is to “produce structural semantic extensions to accommodate the digital publishing industry”.  It has the following structural attributes:

  • doc-abstract
  • doc-acknowledgments
  • doc-afterword
  • doc-appendix
  • doc-backlink
  • doc-biblioentry
  • doc-bibliography
  • doc-biblioref
  • doc-chapter
  • doc-colophon
  • doc-conclusion
  • doc-cover
  • doc-credit
  • doc-credits
  • doc-dedication
  • doc-endnote
  • doc-endnotes
  • doc-epigraph
  • doc-epilogue
  • doc-errata
  • doc-example
  • doc-footnote
  • doc-foreword
  • doc-glossary
  • doc-glossref
  • doc-index
  • doc-introduction
  • doc-noteref
  • doc-notice
  • doc-pagebreak
  • doc-pagelist
  • doc-part
  • doc-preface
  • doc-prologue
  • doc-pullquote
  • doc-qna
  • doc-subtitle
  • doc-tip
  • doc-toc

 

To indicate an the structure of a text box showing an example:

<aside role="doc-example"> <h1>An Example of Structural Metadata in WAI-ARIA</h1> … </aside>

Content expressing a warning might look like this:

<div role="doc-notice" aria-label="Explosion Risk"> <p><em>Danger!</em> Mixing reactive materials may cause an explosion.</p> </div>

Although book-focused, DOC-ARIA roles provide a rich set of structural elements that can be used with many kinds of content.  In combination with the core WAI-ARIA, these attributes can describe the structure of web content in extensive detail.

CSS as Structure

For a long while, developers have been creating pseudo structures using CSS, such as making infoboxes to enclose certain information. Class is a global attribute of HTML, but has become closely associated with CSS, so much so that some believe that is its only purpose.  Yet Wikipedia notes: “The class attribute provides a way of classifying similar elements. This can be used for semantic purposes, or for presentation purposes.”  Some developers use what are called “semantic classes” to indicate what content is about.  The W3C advises when using the class attribute: “authors are encouraged to use values that describe the nature of the content, rather than values that describe the desired presentation of the content.”

Some developers claim that the class attribute should never be used to indicate the meaning of content within an element, because HTML elements will always make that clear. I agree that web content should never use the class attribute as a substitute for using a meaningful HTML element. But the class attribute can sometimes further refine the meaning of an HTML element. Its chief limitation is that class names involve private meanings. Yet if they are self-describing they can be useful.

Class attributes are useful for selecting content, but they operate outside of metadata standards.  However, schema.org is proposing a property that will allow class values to be specified within schema.org metadata.  This has potentially significant implications for extending the scope of structural metadata.

The motivating use case is as follows: “There is a need for authors and publishers to be able to easily call out portions of a Web page that are particularly appropriate for reading out aloud. Such read-aloud functionality may vary from speaking a short title and summary, to speaking a few key sections of a page; in some cases, it may amount to speaking most non-visual content on the page.”

The pending cssSelector property in schema.org can identify named portions of a web page.  The class could be a structure such as a summary or a headline that would be more specific than an HTML element.  The cssSelector has a companion property called xpath, which identifies HTML elements positionally, such as the paragraphs after h2 headings.

These features are not yet fully defined. In addition to indicating speakable content, the cssSelector can indicate parts of a web page. According to a Github discussion: “The ‘cssSelector’ (and ‘xpath’) property would be particularly useful on http://schema.org/WebPageElement to indicate the part(s) of a page matching the selector / xpath.  Note that this isn’t ‘element’ in some formal XML sense, and that the selector might match multiple XML/HTML elements if it is a CSS class selector.”  This could be useful selecting content targeted at specific devices.

The class attribute can identify structures within the web content, working together with entity-focused properties that describe specific data relating to the content.  Both of these indicate content variables, but they deliver different benefits.

Entity-based (descriptive) metadata can be used for content variables about specific information. They will often serve as  text or numeric variables. Use descriptive metadata variables when choosing what informational details to put in a message.

Structural metadata can be used phrase-based variables, indicating reusable components.    Phrases can be either blocks (paragraphs or divs), or snippets (a span).  Use structural metadata variables when choosing the wording to convey a message in a given scenario.

A final interesting point about cssSelector’s in schema.org.  Like other properties in schema.org, these can be expressed either as inline markup in HTML (microdata) or as an external JSON-LD script.  This gives developers the flexibility to choose whether to use coding libraries that are optimized for arrays (JSON-flavored), or ones focus on selectors.  For too long, what metadata gets included has been influenced by developer preferences in coding libraries.  The fact that CSS attributes can be expressed as JSON suggests that hurdle is being transcended.

Conclusion

Structural metadata is finally getting some love in the standards community, even though awareness of it remains low among developers.  I hope that content teams will consider how they can use structural metadata to be more precise in indicating what their content does, so that it can be used flexibly in emerging scenarios such as voice interactions.

— Michael Andrews

The post Structural Metadata: Key to Structured Content appeared first on Story Needle.

Privacytoezichthouders nemen nieuwe guidelines AVG aan

Autoriteit Persoonsgegevens (nieuws) - 11 oktober 2017 - 11:25am
De Europese privacytoezichthouders, verzameld in de Artikel 29-werkgroep (WP29), hebben een aantal nieuwe guidelines aangenomen die bepaalde begrippen uit de Algemene Verordening Gegevensbescherming (AVG) verduidelijken. Het gaat om guidelines voor data protection impact assessment (DPIA) en administratieve boetes.

Businesstester: schakel tussen eindgebruiker en techniek

Computable - 11 oktober 2017 - 10:36am
Financieel detacheerder AP Support heeft in 2016 een nieuwe testprofessional geïntroduceerd: de businesstester. ABN Amro Hypotheken gebruikt vier van AP Supports businesstesters in zijn testteams. Zij maken het leven van Rik Kortlandt (onafhankelijk testmanager ABN Amro)...
Categorieën: ICT , Informatievoorziening

Wifi-technologie in mkb vaak zwaar verouderd

Computable - 11 oktober 2017 - 10:31am
Kleine bedrijven met mobiele medewerkers hebben vaak wifi-netwerken die meer dan acht jaar oud zijn waardoor de connectiviteit in gevaar komt. Oorzaak voor de verouderde apparatuur is dat mkb’ers hun investeringen uitstellen om te wachten op...
Categorieën: ICT , Informatievoorziening

Online reis- en boekingsites blijven geld ophalen

Computable - 11 oktober 2017 - 10:14am
Investeerders stappen nog steeds in online reis- en boekingssites. Zo heeft de Nederlandse startup Withlocals, een marktplaats voor gepersonaliseerde reizen, 3,5 miljoen euro opgehaald in een eerste financieringsronde, geleid door Inkef Capital. Het Britse Secret Escapes,...
Categorieën: ICT , Informatievoorziening

Renault neemt belang in Jedlix

Computable - 11 oktober 2017 - 9:36am
Groupe Renault neemt een belang van 25 procent in Jedlix. Die Nederlandse startup levert een app voor het slim en duurzaam opladen van elektrische auto’s (smart charging). Renault wil via dit partnerschap zijn positie in het...
Categorieën: ICT , Informatievoorziening

Spoelstra spreekt: KiereWiet!

Computable - 11 oktober 2017 - 9:14am
Toen ik hoorde dat het nieuwe kabinet van plan is om als overheid zelf wiet te gaan telen, was het eerste wat ik dacht: ik ben heel benieuwd van wie ze de stroom dan gaan aftappen....
Categorieën: ICT , Informatievoorziening

‘Google start strijd om de woning te veroveren’

Computable - 11 oktober 2017 - 8:15am
Google zet vol in op doordringen en domineren in gewone woningen. De zoveelste ronde. Dit is de discussiestelling die Computable-lezers vandaag krijgen voorgelegd.
Categorieën: ICT , Informatievoorziening

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