"Link Yourself"

21 July 2016
George A. Smathers Libraries at the University of Florida

About this workshop

What is Linked Data? And what can it do for you? This workshop will cover the basics of Linked Data and the Semantic Web, and provide hands-on experience authoring Linked Data. Each participant will create a Friend of a Friend (FOAF) resource about themselves and the people they work with, to understand how Linked Data models let us link data!

Audience members will learn:
The Linked Data Principles
The value of "five-star" Linked Data
The structure of an RDF triple statement
How graph data eases data merger and manipulation



Before we begin

Make sure you have an ORCID ID.

Use the Etherpad for collaborative note-taking.


Linked Data Principles

Tim Berners-Lee, "Linked Data," Design Issues (W3C: 27 July 2006). https://www.w3.org/DesignIssues/LinkedData.html

1) Use URIs as names for things
2) Use HTTP URIs so that people can look up those names
3) When someone looks up a URI, provide useful information, using the standards (RDF, SPARQL)
4) Include links to other URIs, so that they can discover more things


Five-star Linked Data

Available on the web (whatever format) but with an open licence, to be Open Data
★★ Available as machine-readable structured data (e.g. excel instead of image scan of a table)
★★★ as (2) plus non-proprietary format (e.g. CSV instead of excel)
★★★★ All the above plus, Use open standards from W3C (RDF and SPARQL) to identify things, so that people can point at your stuff
★★★★★ All the above, plus: Link your data to other people’s data to provide context


Resource Description Framework

W3C, "Resource Description Framework (RDF)," W3C Semantic Web. https://www.w3.org/RDF/

"RDF is a standard model for data interchange on the Web. RDF has features that facilitate data merging even if the underlying schemas differ, and it specifically supports the evolution of schemas over time without requiring all the data consumers to be changed.

"RDF extends the linking structure of the Web to use URIs to name the relationship between things as well as the two ends of the link (this is usually referred to as a “triple”). Using this simple model, it allows structured and semi-structured data to be mixed, exposed, and shared across different applications.

"This linking structure forms a directed, labeled graph, where the edges represent the named link between two resources, represented by the graph nodes. This graph view is the easiest possible mental model for RDF and is often used in easy-to-understand visual explanations."


Triples

A triple is a three-part statement that relates two resources.

W3C, "RDF 1.1 Primer," W3C Working Group Note. https://www.w3.org/TR/rdf11-primer/

"An RDF statement expresses a relationship between two resources. The subject and the object represent the two resources being related; the predicate represents the nature of their relationship. The relationship is phrased in a directional way (from subject to object) and is called in RDF a property. Because RDF statements consist of three elements they are called triples."

Examples:

Subject predicate object .
Allison eats cookies.
Dave orders pizza.

<http://www.example.com/subject/>
<http://www.example.com/predicate/>
<http://www.example.com/object/> .

<http://www.example.com/subject/>
<http://www.example.com/predicate/>
"object" .

Graph Data

"We can visualize triples as a connected graph. Graphs consists of nodes and arcs. The subjects and objects of the triples make up the nodes in the graph; the predicates form the arcs."


Benefits of Linked Data in Libraries

- Collocation of resources across collections and platforms
- Data interoperability, leading to impromptu merger and analysis
- Inferencing to gain new knowledge from existing metadata
- Search engine optimization


Let's create some data

Go to the "FOAF-a-matic Generator" to create RDF data about yourself and the people you work with.