1. UFCEP6-20-3 Internet Application Development
Rob Stephens
2P27

2. Semantic technologies
Structured data is the new SEO?
Semantic web
Objectives
Technologies
Some practical examples
State of play
For and against

3. Semantic technologies
Current web
Semantic web
URL
URI
Humans
Machines
Documents
Things
Text
Data
Presentation
Semantics
Prose
Properties
Links
Relationships
Exercise
Distinguish URL from URI
Show how RDF works as a data format for the web
There is no impact to the document's presentation.
There is a big (positive) impact on how effectively the document's information can be processed by Web applications.
Tiny changes to Web documents facilitate huge, immediate changes to the overall semantic richness of the Web.

4. Semantic technologies
Enhance machine interpretation
XML: Semiformal documents range between non-formatted texts and fully formatted databases
Microformats and RDFa add semantic attributes to existing web content.
RDF (Resource Description Framework): Structured metadata describe arbitrary heterogeneous Web pages/objects in a homogeneous manner
Machines (e.g. search engines, user agents) can analyze structured data better than full HTML
Ontology: a formal representation of knowledge as a set of concepts within a given domain

5. Search Engine Optimization
Process of ensuring website is visible
Appear among top of search returns
Make search more predictable and reliable
Types of search
Sample
Existence
Exhaustive
Google Webmaster Guidelines
Search is the new navigation?
COI Web standards and guidelines
Structured Data the new SEO?
Global information space for human consumption.
Information and its presentations are mixed up.
Accessible by merely keywords: high recall, low precision
No distinction of the keyword search “Rose” among these concepts: Rational Rose, Guns n Roses, Flower Rose, Rose (Titanic), England’s Rose.
Difficult for machines to automatically comprehend, process, communicate and interoperate.
Problems in information:
finding,
extracting,
representing,
interpreting,
maintaining.

6. Organization of information
Separation of content and presentation
Promotes machine readability
Aides distinguishing things that are presented in the same way, but have different meaning
Content can be presented on a number of devices
Enables accessibility
Tagcloud Example from Wikipedia

7. Organization of information
Classification
Taxonomy
Folksonomy
Ontology
RDF lets you make statements about things but doesn’t say what they mean.
Ontology is a formal representation of the knowledge by a set of concepts within a domain and the relationships between those concepts. It is used to reason about the properties of that domain, and may be used to describe the domain.
Tag gardening, eg Amazon
Tags are multidimensional: users can assign a large number of tags to express a concept and can combine them.
Users can use their own language: words that have meaning for them. These words are likely to be current and reflect local usage.
Users select concepts that have meaning for them as individuals and analyze items to highlight what is important to them.
Tags can be shared, creating knowledge through aggregation
Instead of having to store an item in a single folder, it can be tagged with many different terms and each of these could be used to generate an instant collection (e.g. if a collection of photographs contains photographs with tags such as birthday, family, holiday, Europe, sub-collections can be readily assembled by searching for single tags or pairs.)
Public tagging has been described as having an altruistic appeal, allowing people to contribute to a shared knowledge base. Social tagging fosters the development of communities around similar interests and viewpoints.
Social tagging provides information to professional providers and managers of information about areas of interest and how they are being described. It is a new window on the way our users are thinking and can provide insight into their information needs and habits.
Tagging is very quick, simple and straightforward. Users can apply tags without formal training in classification or indexing.
Disadvantages of folksonomies
The simplicity and ease of use of tagging can result in poorly chosen and applied tags.
Tags can be applied at different levels of specificity by different users (or even by the same user at different times) e.g. the tag cats may be used in one case and animals or pets in another. Or the tag Kitty may simply be used.
Different terms may be used for the same concept (again by different users or by the same user – users will not necessarily be consistent). So felines may be used for some items and cats for others.
Tags with personal meaning only are frequently used (example on Flickr:viewfrommywindow). This tag on its own is of virtually no use to anyone else.
Conversely, the same term can be used for different concepts.

8. The Semantic Web: Definition
The Semantic Web is the abstract representation of data on the World Wide Web (based on the RDF standards and other standards to be defined). (
"The Semantic Web is an extension of the current web in which information is given well-defined meaning, better enabling computers and people to work in cooperation." -- Tim Berners-Lee, James Hendler, Ora Lassila, The Semantic Web, Scientific American, May 2001
The Semantic Web - An Overview

9. The Current Web Resources: identified by URI's untyped Links:
href, src, ...
limited, non-descriptive
Humans:
Characteristics of the documents is (normally) clear to those with a grasp of English.
Machines:
Very little information available.

10. The Current Web Global information space for human consumption.
Information and its presentations are mixed up.
Accessible by merely keywords: high recall, low precision
No distinction of the keyword search “Rose” among these concepts: Rational Rose, Gun n Roses, Flower Rose, Rose (Titanic), England’s Rose.
Difficult for machines to automatically comprehend, process, communicate and interoperate.
Problems in information:
finding,
extracting,
representing,
interpreting,
maintaining.

11. The Semantic Web Resources: Common naming syntax (URI's) Links: User:
Richer user experience
Machine:
More processable information is available
Computers and people:
Work, learn and exchange knowledge effectively

12. Semantic Web: The Web of Reason
The “Next Generation Web” with well-established infrastructure for expressing information in a
Precise,
Human-readable, and
Machine-interpretable form.
Enable syntactic and semantic interoperability among independently-developed Web applications, allowing them to efficiently perform sophisticated tasks for humans.
Enable Web resources to be accessible by their semantics rather than by keywords and syntactic forms.
Enable inference:
Benny Andersson is a member of ABBA.
ABBA won the Eurovision Song Contest.
Hence, Benny Andersson is a Eurovision winner.

13. Semantic technologies: The BBC
The choice of the BBC
Use external, public datasets
Wikipedia, MusicBrainz, …
They are available as data
not API-s or hidden on a Web site
data can be extracted using, eg, HTTP requests or standard queries
In short
Use the Web of Data as a Content Management System
Use the community at large as content editors
There are more an more data on the Web
government data, health related data, general knowledge, company information, flight information, restaurants,…
More and more applications rely on the availability of that data

14. Semantic technologies: Google
Rich Snippets
Knowledge Graph
Semantic search
Google Now (aka Google Assistant)
Voice enabled semantic search
WebTables
Extracts relational-style data from the Web expressed using the HTML table tag
Adds meta-data tags (from extracted relations)
Deep Web Crawler
surfaces content for several million Deep Web databases by interrogating forms
Adds tags
Traditional search engines are tuned to return relevant documents, not data sets, so users searching for data are generally ill-served. Using the extracted WebTables data, we implemented a search engine that takes a keyword query and returns a ranked list of databases instead of URLs
Not all structured data on the Web is published in easily accessible HTML tables. Large volumes of data stored in back-end databases are often made available to Web users only through HTML form interfaces; for example, a large chain of coffeehouses might have a database of store locations that are retrieved by zip code using the HTML form on the company's Web site, and users retrieve data by performing valid form submissions.
"Deep," "Hidden," and "Invisible Web" have all been used to refer to the content accessible only through forms

15. Semantic web stack Authentication, trustworthiness of statements
Establish truth of statements, infer unstated facts
Vocabularies, shared meanings
RDF resources types
Meta data, “say anything about anything”
Data types and structure
Common syntax