Thursday, September 8, 2011

IFI7101: Session 7


Lecture and seminar by David Lamas

Driving question:

How do we go about pushing interactive media closer to the Semantic Web and the Internet of Things concepts?

Metadata

The term metadata is an ambiguous term which is used for two fundamentally different concepts (types). Although the expression "data about data" is often used, it does not apply to both in the same way. Structural metadata, the design and specification of data structures, cannot be about data, because at design time the application contains no data. In this case the correct description would be "data about the containers of data". Descriptive metadata, on the other hand, is about individual instances of application data, the data content. In this case, a useful description would be "data about data contents" or "content about content" thus metacontent.

Metadata (metacontent) is traditionally found in the card catalogs of libraries. As information has become increasingly digital, metadata is also used to describe digital data using metadata standards specific to a particular discipline. By describing the contents and context of data files, the quality of the original data/files is greatly increased.

For example:
  1. A webpage may include metadata specifying what language it's written in, what tools were used to create it, and where to go for more on the subject, allowing browsers to automatically improve the experience of users.
  2. A digital image may include metadata that describes how large the picture is, the color depth, the image resolution, when the image was created, and other data. Metadata may be written into a digital photo file that will identify who owns it, copyright and contact information, what camera created the file, along with exposure information and descriptive information such as keywords about the photo, making the file searchable on the computer and/or the Internet. Some metadata is written by the camera and some is input by the photographer and/or software after downloading to a computer.
Metadata on the Internet

The HTML format used to define web pages allows for the inclusion of a variety of types of metadata, from basic descriptive text, dates and keywords to further advanced metadata schemes such as the Dublin Core, e-GMS, and AGLS standards. Pages can also be geotagged with coordinates. Metadata may be included in the page's header or in a separate file. Microformats allow metadata to be added to on-page data in a way that users do not see, but computers can readily access.

Interestingly, many search engines are cautious about using metadata in their ranking algorithms due to exploitation of metadata and the practice of search engine optimization, SEO, to improve rankings. See Meta element article for further discussion.

Ontology

In computer science and information science, an ontology formally represents knowledge as a set of concepts within a domain, and the relationships between those concepts. It can be used to reason about the entities within that domain, and may be used to describe the domain.

Ontologies are the structural frameworks for organizing information and are used in artificial intelligence, the Semantic Web, systems engineering, software engineering, biomedical informatics, library science, enterprise bookmarking, and information architecture as a form of knowledge representation about the world or some part of it.

Examples of applications using ontology engines

SAPPHIRE or Situational Awareness and Preparedness for Public Health Incidences and Reasoning Engines is a semantics-based health information system capable of tracking and evaluating situations and occurrences that may affect public health.

Folksonomy

A folksonomy is a system of classification derived from the practice and method of collaboratively creating and managing tags to annotate and categorize content; this practice is also known as collaborative tagging, social classification, social indexing, and social tagging.

Folksonomies became popular on the Web around 2004 as part of social software applications such as social bookmarking and photograph annotation. Tagging, which is one of the defining characteristics of Web 2.0 services, allows users to collectively classify and find information. Some websites include tag clouds as a way to visualize tags in a folksonomy.

A good example of a social website that utilizes folksonomy is 43 Things, a social networking website that is built on the principles of tagging, rather than creating explicit interpersonal links (as seen in Friendster and Orkut). Users create accounts and then list a number of goals or hopes; these goals are parsed by a lexer and connected to other people's goals that are constructed with similar words or ideas.

The Semantic Web

The Semantic Web is a "man-made woven web of data" that facilitates machines to understand the semantics, or meaning, of information on the World Wide Web. The concept of Semantic Web applies methods beyond linear presentation of information (Web 1.0) and multi-linear presentation of information (Web 2.0) to make use of hyper-structures leading to entities of hypertext.

It extends the network of hyperlinked human-readable web pages by inserting machine-readable metadata about pages and how they are related to each other, enabling automated agents to access the Web more intelligently and perform tasks on behalf of users. The term was coined by Tim Berners-Lee, the inventor of the World Wide Web and director of the World Wide Web Consortium ("W3C"), which oversees the development of proposed Semantic Web standards. He defines the Semantic Web as "a web of data that can be processed directly and indirectly by machines."

"Semantic Web" is sometimes used as a synonym for "Web 3.0", though each term's definition may vary depending on whom you ask. Many believe that Web 3.0 is the "next big thing"[citation needed] but there only lies speculation as to just what that might be. It will be an improvement in the respect that it will still contain Web 2.0 properties while continuing to add to its ever expanding lexicon and library of applications.





The Internet of Things

The Internet of Things refers to uniquely identifiable objects (Things) and their virtual representations in an Internet-like structure. The concept of the Internet of Things has become popular through the Auto-ID Center. Radio-frequency identification (RFID) is often seen as a prerequisite for the Internet of Things. If all objects of daily life were equipped with radio tags, they could be identified and inventoried by computers. However, unique identification of things may be achieved through other means such as barcodes or 2D-codes as well.

Although the idea is simple, its application is difficult. If all objects in the world were equipped with miniscule identifying devices, daily life on our planet could undergo a transformation. Such a system could greatly reduce the chances of a company running out of stock or wasting products, as all involved parties would know exactly which products are required and consumed. Mislaid items and physical theft would be affected by the fact that the location of an item would be known at all times.



Concept map:

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