Introduction to Semantic Metadata & Semantic Web Organizing Information & Metadata
Semantic Metadata & Semantic Web Semantic Web is all about data. So we need to understand first what is data and metadata DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web Lecture Outline Metadata Examples Metadata Definition Controlled Vocabulary: Thesaurus; Ontology Uncontrolled Vocabulary Structured vs. Unstructured Data Purposes of Metadata Important Distinctions between Metadata DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Three different Metadata examples These slides Book “London to Lahore” on Internet archives website “National Anthem” video on Youtube DCS GCU - FS 2013 Semantic Metadata & Semantic Web
Metadata about “these slides” Course Name or Title Lecture Topic or Title Lecturer or Creator Organization Lecture Date Semester Class Schedule Place Pieces of metadata: Tells something useful about lecture/course Obtained from timetable or slides It is about lecture, not about the content of lecture DCS GCU - FS 2013 Semantic Metadata & Semantic Web
Internet Archives Example https://archive.org/details/londontolahore00unkngoog Internet Archives Example DCS GCU - FS 2013 Semantic Metadata & Semantic Web
Metadata of video (Youtube) Related videos
Semantic Metadata & Semantic Web Video Metadata lot of metadata (besides video) Some Metadata is free text (e.g. description) while other is selected from given (e.g. category) Different creators, different processes, different Metadata Up-loader of video (e.g. title; category; description etc) Viewers (e.g. comments) Youtube computer algorithm (e.g. viewers’ count; related videos etc) DCS GCU - FS 2013 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web Diversity of Metadata The information or description is about the object being discussed and not about the content of object This description is actually Metadata about objects Different types of processes are used for different types of Metadata Metadata can be general, specific to objects, specific to applications General: creator, title Object Specific: lecture slides (schedule); book (page count); video (video duration) Application Specific: scanner; scan date; comments; tags DCS GCU - FS 2013 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web Metadata in Technology News DCS GCU - FS 2014 Semantic Metadata & Semantic Web
The USA NSA and Metadata Metadata associated with mobile calls: # of the phone making the call # being called ID of the cell tower (to approximate locations) Time & duration of the call Cell phone subscribers data DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web Metadata is data DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web For Location-based services (e.g. Google Maps) Metadata (coordinate) used by GPS devices Recommendations based on physical location Metadata is everything else (Except actual content) Metadata is data Fuzzy distinction between data and metadata Context sensitive DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web OS X Mavericks Tags in finder Tags in a document DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Descriptive metadata for organizing and searching files Tags in finder DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web Tags in a document Term tags is used for metadata interchangeably DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Firefox Bookmark Tags in Firefox DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web Lecture Outline Metadata Examples Metadata Definition Controlled Vocabulary: Thesaurus; Ontology Uncontrolled Vocabulary Structured vs. Unstructured Data Purposes of Metadata Important Distinctions between Metadata DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web Metadata = Data About Data Metadata = Description Two questions: Description of what? (practical question) What does it mean to describe something (more philosophical) DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Description of Anything Description of What? Description of Anything Physical Digital Natural Artificial DCS GCU - FS 2014 Semantic Metadata & Semantic Web
A statement about Something Something is Subject Descriptor is Object Predicate is relationship between Subject and Object DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web Data about anything DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Metadata = Description Descriptive statements are the simplest things you can say about something. DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web Description DCS GCU - FS 2014 Semantic Metadata & Semantic Web
What does it mean to describe something? What is description? What does it mean to describe something? Examples: describing books in libraries for the purpose of storage and later retrieving them Describing animals in zoo to help people understand what they are looking for DCS GCU - FS 2014 Semantic Metadata & Semantic Web
e.g. access points for books Title Author Subject Access points are made of descriptive metadata e.g. access points for books DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Descriptive metadata examples DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Administrative metadata Administrative metadata provides information to help manage or administer something. DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web Subject Analysis DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web Subject Analysis Object: These Slides Subject: Organizing Information; Metadata; Semantic Web Titles are not always a good indication of what’s something is about. Subject Analysis is usually subjective DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web Subject Analysis Books titles are not always descriptive Object: Bang-e-Dara (The Call of the Marching Bell). Subject: Philosophical poetry Poems Self-esteem Figuring out significant characteristics of things being described DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web Item-level vs. Collection-level Description DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Item = single object Collection = collection of objects DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Example (http://exhibitions.europeana.eu/) DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Collection-level description DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Item-level description DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web Subject Headings DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Library of Congress Subject Headings (LCSH) A descriptive metadata schema Subject heading for use in bibliographic records Possibly covers all human knowledge By using LCSH, libraries collect, organize and disseminate documents Applied to every item within a library’s collection DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web Library of Congress Subject Headings (LCSH) http://id.loc.gov/authorities/subjects.html LCSH provides subject heading terms to describe anything with a subject DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Thesaurus or Controlled Vocabulary DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Not a thesaurus or a controlled vocabulary A snapshot of language Not a thesaurus or a controlled vocabulary DCS GCU - FS 2014 Semantic Metadata & Semantic Web
LCSH – controlled vocabulary Organizational control over vocabulary DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web Thesauri DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web Thesaurus List of words Relationships between words Synonymy Antonymy DCS GCU - FS 2014 Semantic Metadata & Semantic Web
MeSH – controlled vocabulary Narrower but deeper http://www.nlm.nih.gov/cgi/mesh/2014/MB_cgi DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web Hierarchy of Terms / Family Tree / organization Chart Hierarchy tree is used to represent terms and relationships between them DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Standard terms for entities UF : Use For Thesaurus also defines standard terms for entities DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Entity and Relationships DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web Faceted Classification DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web Logic of controlled vocabulary is dependent on what you want to do with it. On description side, faceted classification allows richer description of objects along multiple axes. To describe things according to more than one characteristic or attribute. On retrieval side, objects can be searched precisely using specific terms. DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web http://search.lib.unc.edu DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web A library item can be described in multiple ways and later can be searched by several different facets. DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web Ontology DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web Meaning Philosophy: Study of the nature of existence, what categories of things exist, & what their relationships are Information Science: Formal representation of a set of concepts within a domain Computer Science: An ontology is an explicit and formal specification of a conceptualization DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web Thesauri for natural languages DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web Thesaurus LCSH DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Personal Ontology example http://www.cs.umd.edu/projects/plus/SHOE/onts/personal1.0.html Ontologies are for some specific domains but describe more complex relationships and inference rules than thesauri. Personal ontology is related to individual people Set of categories of objects within Personal universe Complex relationships between categories or objects Allows inferences DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web FOAF Ontology http://dbpedia.org/page/Friend_of_a_friend FOAF ontology is related to “friend of a friend” Set of categories of objects within FOAF universe Complex relationships between categories or objects Allows inferences DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web Uncontrolled Vocabulary DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Tags are example of uncontrolled vocabulary No control over vocabulary DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web Flickr example Lahore Fort DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web Tags cloud DCS GCU - FS 2014 Semantic Metadata & Semantic Web
“Map is not a Territory” Alfred Korzybski DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web Matadata is a Map Metadata simplifies the complex conceptual space of the world, for example LCSH is not that much complex that the entire scope of human knowledge It provides a large but a finite set of terms to describe that complex conceptual space You do not need to know whole LCSH controlled vocabulary to use some particular term LCSH is a Map and the scope of all human knowledge is Territory. DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web Purposes of Metadata DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Metadata IS NOT always describing the features of a thing Types of Metadata Metadata IS NOT always describing the features of a thing Descriptive Metadata E.g. title; author; publication year; file format etc Structural Metadata Description of the structure/organization of a compound object. e.g: book chapters sections pages Administrative Metadata Description of how an object can or should be stored or cared for e.g. Copyright or intellectual property rights; access permissions; origin etc DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web Some important distinctions about Metadata Record DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Important distinction # 1: Level Item Collection What is the Metadata record describing? DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Important distinction # 2: Location Embedded Linked Where is Metadata record? DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Bibliographic Metadata record is embedded in the object DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web Library card is an example of Linked Metadata record that is located separately from the original object DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Important distinction # 3: Audience Human-readable Machine-readable Who is the Metadata for? DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web Machine Readable Cataloging (MARC) Record DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web Conclusion DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Metadata = Description DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Descriptive Structural Administrative DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Controlled Vocabulary Uncontrolled Vocabulary DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web Thesaurus Ontology DCS GCU - FS 2014 Semantic Metadata & Semantic Web
Semantic Metadata & Semantic Web Level: Item vs. Collection Location: Embedded vs. Linked Audience: Human- vs. Machine-readable DCS GCU - FS 2014 Semantic Metadata & Semantic Web