Introductory resources for learning about Linked Data (the “semantic web”) and RDFa

I was asked to collect together some introductory information on Linked Data (which will help create the “semantic web”) and RDFa, and thought I may as well post it here in case it’s of use to anyone else who’s interested in the subject and who doesn’t already understand the basic concepts.

Key concept

The worldwide web enabled us to link documents. Now we want to link data that lies within those documents.

Including linked data in a machine-readable (as well as a human-readable) format blows open the possibilities of what we can do with it.

Introduction

Tim Berners-Lee on the next Web (TED talk)

If this doesn’t get you excited, don’t bother with the rest of this post. ;)

Intro to the Semantic Web

Helps with recognising importance of using semantics and gives some examples of possible uses of linked data.

Beyond Web 2.0 – How RDFa Can Help to Democratise Data on the Web  (Google Tech Talk)

RDFa Basics (short video)

Introduces the fundamental method used by RDFa and the triple.

A Short Introduction to Semantic Web-based E-Commerce: The GoodRelations Vocabulary

Introduction to RDFa (A List Apart article)

Introduction to RDFa II (A List Apart article)

General information and help

DERI Linked Data Research Centre RDFa cheat sheet

W3C RDFa Primer

RDFa for HTML Authors (W3C article)

W3C Linked Data Tutorial

RDFa Wiki (a RDFa community)

GoodRelations (a vocabulary designed for e-commerce)

RDFa news

rdfa.info

Searching with RDFa

RDFa and SEO

Google’s Social Graph API, RDFa and the future of web search

Introducing Rich Snippets (Google)

Help us make the web better: An update on Rich Snippets (Google)

Yahoo Search Monkey

W3C RDFa distiller

Try this Tesco product page in the above distiller:

http://www.clothingattesco.com/menswear/Onebody-Ski-gloves/invt/ew921763

Simple use case example

My web page – a XHTML document which presents some information about me in human-readable form:

1. I know Ian Oliver (see text under Firefox car);
2. what social media accounts I have (LinkedIn, twitter and Flickr).

The linked data (machine-readable form) in my XHTML document as extracted by W3C’s RDFa distiller (must be viewed with an XML-capable browser – not IE)

Scenario: someone who knows (of) David Oliver wants to find him at social networks.

With no linked data, a search for David Oliver relies on keywords (e.g. “David” and “Oliver”), producing many returned results (there are lots of people called David Oliver).

With the linked data from http://doliver.co.uk/, a properly defined search would produce only results that were derived from “http://doliver.co.uk/#me” – precisely those desired and no others (the three social networking accounts).