Schema
A schema is a form of classification system which catalogues information. There are many types of schemas in broad use worldwide. For example, schemas for software applications are descriptions of the format and structure of a given document or application's data (contents), and is commonly used in Information Technology by programmers, technologists and developers within many industries for sharing (sending/receiving) data between applications. In the study of Computer Science, schema is akin to Object-Oriented concepts where data is embodied in classes, but in the case of a web schema, the schema is represented by well-defined, textual descriptions which use a specific syntax (such as XML or RDF) to describe the form and structure a given item of data should follow (or can be expected to follow).
Contents
Early Schemas
One of the earliest formal library cataloguing schemas (upon which the popular library Dewey Decimal & Universal Decimal Classification systems were eventually based) is known as the Mundaneum.
000 Science and Knowledge. Organization. Computer Science. Information Science. Documentation. Librarianship. Institutions. Publications 100 Philosophy. Psychology 200 Religion. Theology 300 Social Sciences 400 vacant 500 Mathematics. Natural Sciences 600 Applied Sciences. Medicine, Technology 700 The Arts. Entertainment. Sport 800 Linguistics. Literature 900 Geography. History
- wikipedia: Dewey Decimal Classification ("Dewey Decimal System", the original information archival/retrieval system designed for "libraries with 20,000 or future archives")
000 – General works, Computer science and Information 100 – Philosophy and psychology 200 – Religion 300 – Social sciences 400 – Language 500 – Pure Science 600 – Technology 700 – Arts & recreation 800 – Literature 900 – History & geography
Services
SchemaPedia
SchemaPedia was basically a Web 2.0, user-contributed and updated version of the centrally managed SchemaWeb, built by Ian Davis at Talis. It provides a schema directory, search functions and the ability to store/manage information about your data schema.
- SchemaPedia: https://web.archive.org/web/20110308201847/http://schemapedia.com/schemas/ | EXAMPLE - MobileTV
- PURL: http://purl.org (most schemas/ontologies use this to preserve their URL mapping against any changes)
SchemaWeb
SchemaWeb is a directory of RDF Schemas expressed in the RDFS, OWL and DAML+OIL schema languages. SchemaWeb is a place for developers and designers working with RDF. It provides a comprehensive directory of RDF Schemas to be browsed and searched by human agents and also an extensive set of web services to be used by software agents that wish to obtain real-time schema information whilst processing RDF data.
RDF Schemas are the critical layer of the Semantic Web. They provide the semantic linkage that 'intelligent' software needs to extract value giving information from the raw data defined by RDF triples.
- SchemaWeb: http://www.schemaweb.info/
- SchemaWeb - Web Services: http://www.schemaweb.info/webservices/WebServices.aspx
Schema.org
Schema.org, also known as OpenSchema has emerged as the leading "Web 3.0" specification for marking up website content to share structured data about your data whether structured or unstructured.
- Schema - Search Engine Metadata protocol: http://schema.org | ONTOLOGY | LOD
- Yandex - HTML5 Microdata test tool: https://webmaster.yandex.ru/microtest.xml (Russia's leading Search Engine)
- Google - HTML5 Microdata test tool: https://developers.google.com/structured-data/testing-tool/
- HTML5 Microdata - Rich Snippet Generator: http://tools.ranksider.com/rich-snippets (supports: Event, Recipe, Product, Organization, Music, Review, People)
- HTML5 Microdata spec: https://html.spec.whatwg.org/multipage/microdata.html
- wikipedia: Microdata (HTML)
- W3C working group for Schema.org: https://www.w3.org/community/schemaorg/ | OFFICIAL W3C PAGE
[8] [9] [10] [11] [12] [13] [14]
Tutorials
- Beyond Rich Snippets -- Semantic Web Technologies for Better SEO: http://www.seoskeptic.com/beyond-rich-snippets-semantic-web-technologies-for-better-seo/
- SERP 101 -- All About Search Engine Results Pages: http://www.wordstream.com/serp
- Diagrams and Data Explorer for MongoDB: http://dzone.com/articles/diagrams-and-data-explorer-for-mongodb (still thinking in "schemas" with NoSQL? try DBschema to visualize virtual foreign keys)
External Links
- wiki: Schema
- wikipedia: Canonical schema pattern
- wikipedia: Single source of truth
- Canonical Data Model (CDM): http://www.enterpriseintegrationpatterns.com/patterns/messaging/CanonicalDataModel.html
- Texas Student Data System - Canonical Data Model Design Guidelines: http://www.cissmart.com.br/webcontent/material/CDM_Design_Guidelines.pdf
- SOA and Canonical Data Model (CDM): http://www.eai-ideas.com/architecture-ideas/soa-and-canonical-data-model-cdm
- Why You Should Avoid a Canonical Data Model: http://www.innoq.com/en/blog/thoughts-on-a-canonical-data-model/
- Benefits of a Canonical Data Model (CDM) in a SOA environment: https://technology.amis.nl/2016/08/08/soa-benefits-of-a-canonical-data-model/
- Canonical Data Modeling- A quick start-up primer: https://www.linkedin.com/pulse/canonical-data-modeling-quick-start-up-primer-tarun-gupta
- Global versus Local -- A Collectively Developed Set of Schema Design Guidelines: http://xfront.com/GlobalVersusLocal.html
- Schema Design Patterns -- Garden of Eden: https://blogs.msdn.microsoft.com/skaufman/2005/05/10/schema-design-patterns-garden-of-eden/
- Schema Design Patterns -- Venetian Blind: https://blogs.msdn.microsoft.com/skaufman/2005/04/29/schema-design-patterns-venetian-blind/
- Schema Design Patterns -- Salami Slice: https://blogs.msdn.microsoft.com/skaufman/2005/04/25/schema-design-patterns-salami-slice/
- Schema Design Patterns -- Russian Doll: https://blogs.msdn.microsoft.com/skaufman/2005/04/21/schema-design-patterns-russian-doll/
- Venetian Blinds vs Garden of Eden patterns for industry standards XML Schemas: http://lists.xml.org/archives/xml-dev/201010/msg00051.html
- Subtyping in W3C XML Schema, Part 1 -- "Garden of Eden" CDM: http://tdan.com/subtyping-in-w3c-xml-schema-part-1/7185
- Garden of Eden -- XML Schema: http://wiccentmati.files.wordpress.com/2015/10/garden-of-eden-xml-schema.pdf
- Global attributes -- pros & cons: http://stackoverflow.com/questions/20755589/global-attributes-pros-and-cons
- What is the fastest way to access huge XMLs in salami slice format?: http://stackoverflow.com/questions/32335546/what-is-the-fastest-way-to-access-huge-xmls-in-salami-slice-format
- 3 different XML design styles -- Russian Dolls,Salami Slice,and Venetian Blind: http://timzhao.blogspot.ca/2010/09/3-different-xml-design-styles-russian.html
- Introducing Design Patterns in XML Schemas: http://www.oracle.com/technetwork/java/design-patterns-142138.html
References
- ↑ Schema.org and One Hundred Years of Search: http://danbri.org/words/2012/07/18/793
- ↑ A vision of computers before they existed: http://www.youtube.com/watch?v=LskVjSrZ_2M (predicted computer screen/display technology, the internet, world wide web, speech recognition, information storage/retrieval, and, search engines... for more see 2002 documentary "The Man Who Wanted To Classify The World")
- ↑ Paul Otlet from a historian on Classification: http://www.youtube.com/watch?v=N_oLH0B9Sac
- ↑ Google, Bing & Yahoo's New Schema.org Creates New Standards for Web Content Markup: http://www.readwriteweb.com/archives/every_site_on_the_web_will_consider_google_bing_ya.php
- ↑ Is Schema.org Really a Google Land Grab?: www.readwriteweb.com/archives/is_schemaorg_really_a_google_land_grab.php
- ↑ ‘‘‘Introducing Rich Cards’’’ (a step up from Rich Snippets built on JSON+LD version of OpenSchema): https://webmasters.googleblog.com/2016/05/introducing-rich-cards.html?m=1
- ↑ Google Search - Features: https://developers.google.com/search/docs/guides/search-features
- ↑ Getting started with schema.org using Microdata: https://schema.org/docs/gs.html#microdata_itemscope_itemtype
- ↑ Schema.org - OpenSchema issues list: https://github.com/schemaorg/schemaorg/issues (place to make suggestions or requests for new types to be added, changes, etc)
- ↑ 2011-2014 Proposals for Schema.org (ARCHIVED): https://www.w3.org/wiki/index.php?title=WebSchemas/SchemaDotOrgProposalsArchive#2011-2014_Proposals_for_Schema.org
- ↑ Microdata, RDFa or JSON-LD Appropriate or best usage?: https://stackoverflow.com/questions/26906367/microdata-rdfa-or-json-ld-appropriate-or-best-usage
- ↑ SCHEMA.ORG -- Web Schemas - Periodicals Comics: http://www.w3.org/wiki/WebSchemas/PeriodicalsComics (schema.org datatype)
- ↑ Schema Markup Best Practices – Json-LD Vs Microdata: https://envigo.digital/blog/seo/schema-markup-best-practices-json-ld-vs-microdata
- ↑ SCHEMA.ORG -- Web Schemas - Movie: https://schema.org/Movie | EXAMPLE-Microdata
See Also
RDF Schema | XML Schema | SQL Schema | OpenSchema | JSON+LD
