Services on linked data
LD4L Workshop Breakout Session, Tuesday, February 24
Risk of not knowing what to search for
- Providing discovery endpoints
- ‘hardened’ SPARQL endpoints may be less prone to down time – e.g., Fuseki documentation states that "authentication and control of the number of concurrent requests can be added using an Apache server"
- publishing starting points with examples and standard extracts may help
- emulate Social Explorer http://socialexplorer.com as a way to query the contents of a larger data source, in that case census data
- the linked data fragments technology (http://linkeddatafragments.org) may facilitate hosting linked data without the server-side overhead and risk of a public SPARQL endpoint
- VIVO/Vitro 'rich export' – augmenting standard linked data responses with standard queries
- e.g., get all a person's publications from a single request rather than client having to issue multiple requests
- Semantic Web crawling leveraging HTML web crawler experience
Synchronizing harvested information
- Risk of harvested or aggregated information going out of sync
- Resource sync standard addressed the need to repeatedly synchronize and update
Desire to be able to query on different axes
- e.g., query OCLC Works by VIAF identifier to get a list of works by that author
Reconciliation services
- not necessarily centralized or monopolies
- would work best in an iterative mode, with curation and provenance to manage difference of opinion (or evidence)
- incorporate feedback from users
- need protocols – could leverage a common API for reconciliation building on the OpenRefine API — specify as much metadata as you have, get ranked results back
- surface (publish) the results
- sameAs.org
Validation
- RDF data shapes working group
- DCMI tutorial on RDF validation
- Linked data needs mashup tools that test connections and illustrate bringing data together
Ontology extension mechanisms
- Schema.org extensions being proposed and managed on GitHub
Ability to push bookmarks
- Small graphs of data, consumable by others, to a platform similar to Mendeley but not limited to bibliographic material
- A service where I can push the results of my search, organized by topic
- Add things to a collection I have
- Similar to an annotation service
- You search, you refine it, you step back — now only save as bookmarks at one level
- Nobody can use your web bookmarks now
centralized entity mapping
feedback by users on the mapping
need protocols
want to discover annotation — known servers with protocols
collections have been done by many different places
if we do linked data, my list is a list of URIs from many sources
on the UI won’t see that
assuming accessible SPARQL endpoints
3
other cleanup tasks — validation? consistency of ontology use
entity recognition — text mining or analytics for tools — autotaggers
4
constant crawling graphs of linked data
semantically aware web crawling — is it worth going down this path, what’s attached, what has changed
5
provenance space — who’s made a particular assertion for that
in the library domain, could imagine a layer about who’s responsible for an assertion
unspecified.
crowd sourcing — as move up toward the general public, typically track less who did it
variable credibility
acknowledge that
nanopublications
===== group 4 ====
reconciliation services — contains no data, queries a distributed set of resources
individual libraries will become the authorities for special collections — items, people, events
queries to a central area would find a match
cache the sameAs so don’t have to re-query
everybody who consumes has the cross-links
the sort of thing that OCLC might end up doing —
could be any type of object — logical to start with works
brings up the questions of the degrees of sameAs ness
when a new match is known, publish that — a notification mechanism
you would provenance those links to indicate where came from
used to be a plug-in for Netscape where a side-wiki and annotate — anybody could see what everyone else had done
now in the world of unique identifiers — a linkerator - for people to rank what they see
build up ant trails over time, around an object
how to make it in any way central — get it to the browser
how about the annotation example?
regular expressions against EAD for an object to suggest what they link to
feed into a system to validate
then give pointers to the link
other levels of relationship than sameAs
over time it would aggregate and
a clustering algorithm — the more a link is traversed, the space reduces
emergence sorting
software crawling the graph - how do you figure out what to trust? the world according to professor X or Y
trust is very tricky
a page rank algorithm for linked data — more for asserters
strenghthen the nodes to repeat confidence
repeating assertions in multiple repositories — I agree with them, the +1 or thumbs up
Reddit gets a lot of traction
nanopublications
if you reify assertions — to add confidence where have more knowledge or curation
confidence levels
wikipedia has a way to accept
no confidence in semantic search engines
too siloed
visualizations have to be crafted
