From Idea to WebCreating Linked Data Apps

SemTechBiz Berlin 06.02.2012

#php #javascript #semweb #kasabi

bn@kasabi.com@bengee

Benjamin Nowack

Linked Data Essentials

SemTechBiz Berlin 06.02.2012

Data objects with

● properties

● links to other objects

Linked Data Essentials

SemTechBiz Berlin 06.02.2012

HTTP identifiers for

● objects

● property names

● link names

Linked Data and the Semantic Web

SemTechBiz Berlin 06.02.2012

The Linked Data Ecosystem

SemTechBiz Berlin 06.02.2012

New Possibilities (and Challenges)

SemTechBiz Berlin 06.02.2012

● Distributed, re-usable data and schemas

● Schema-less, fully indexed storage systems

● Uniform interfaces (HTTP + flattened graph model)

● Open extensibility / annotations

● Free-form analytics

● Aggregation / Integration

● Inference

Typical App Scenarios for Linked Data

SemTechBiz Berlin 06.02.2012

● Analytics & Visualisations

● Context-aware widgets and UI elements

● UGC / Annotations

● Filtered Aggregations

● Flexible Navigators

● Mashups

● KM

Before you start

SemTechBiz Berlin 06.02.2012

● What is your objective?

● Dataset, Tool or Application?

● Charity or Business?

● Pick one app scenario at a time.

● Set a time-frame.

By Example...

SemTechBiz Berlin 06.02.2012

1) Problem Identification

SemTechBiz Berlin 06.02.2012

● 3 days left until SemTech Biz Berlin (ugh!)

● 1st SemTech in DE

● (Hopefully) many new faces interested in applying

the technology

● Getting started with specs and tools to build an app

can be tricky.

● Generally, finding your way around in the semantic

technology space is not necessarily obvious.

2) App Idea & Possibilities

SemTechBiz Berlin 06.02.2012

● Show, don't tell...

● A behind-the-scenes demo could be helpful

● The SemTech conference organizers make their data

available (Thanks, Eric!)

● Build a basic graph navigator. Demonstrate lessons

learned and challenges

● Domain browser as a handy by-product.

● 3 days? Should be easy, no?!

3) Simple User Stories help to stay focused

SemTechBiz Berlin 06.02.2012

● Get access to all (well, many) semantic tech

resources in one place (experts, topics,

companies, talks, ...)

● Allow exploration by simply “Following links”.

● Find outgoing as well as incoming relations .

● Provide statistics using the aggregated

information.

4) Create a UI Sketch and Interaction Idea

SemTechBiz Berlin 06.02.2012

5) Design the basic UI Elements

SemTechBiz Berlin 06.02.2012

5b) Think Widgets

SemTechBiz Berlin 06.02.2012

6) Create your UI in code (CSS FTW!)

SemTechBiz Berlin 06.02.2012

7) Create a Schema Sketch:

SemTechBiz Berlin 06.02.2012

7b) Schema in simple code:

SemTechBiz Berlin 06.02.2012

8) URL/Path Considerations

SemTechBiz Berlin 06.02.2012

/ Welcome

/ TYPE List of items of type TYPE

/ TYPE / ID Description of item ID

/ TYPE / ID / LINK Related items of type LINK

/conferences/semtech2010/speakers

8b) Let clean URL structures enable Automation

SemTechBiz Berlin 06.02.2012

/conferences/semtech2010/speakers;country=UK

SELECT ?speaker WHERE {

?conference rdf:type app:Conference .

?conference app:id “semtech2010” .

?conference app:speaker ?speaker .

?speaker app:country “UK” .

}

(... 2 days left)

SemTechBiz Berlin 06.02.2012

9) Code!

10) External Data needed!

SemTechBiz Berlin 06.02.2012

● Identification of needed data sources

● semtech data

● country identifiers

● Conversion to internal, app-specific model

● Alternative: re-use source ontology

● Clean-up and harmonisation („Reconciliation“)

● Import or use a stand-alone service

(... 1 day left)

(... 1 day night left)

SemTechBiz Berlin 06.02.2012

11) Get the basic widgets in place.

Next Steps

SemTechBiz Berlin 06.02.2012

● Use the app and revisit the user stories

● Now you can start having fun with

automation/abstraction

● Add more powerful widgets

● Export the augmented/curated data to support

the ecosystem. (Did I mention Kasabi?)

● Create and publish link sets

semtech360.com

(work in progress)

SemTechBiz Berlin 06.02.2012

Trimming the Learning Curve

SemTechBiz Berlin 06.02.2012

● Keep your existing tools (where possible)

● Specs matter. Time-to-launch matters more

● Late URI binding

● Create per-app schemas

● Don't generalise and automate right away

● (Re-)Publishing is the easy part

● Grab a SPARQL tutorial & play 2h with LOD stores.