Services on linked data
LD4L Workshop Breakout Session, Tuesday, February 24
facilitator: Jon Corson-Rikert
Risk of not knowing what to search for
may be addressed by
- Providing discovery endpoints and what they hold
- ‘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"
- standard extracts and publishing starting points with examples may 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
Synchronizing harvested information
- Risk of harvested or aggregated information going out of sync
- Resource sync standard addressed the need to repeatedly synchronize and update
risk of not knowing what to search for
publish starting points & examples of queries and/or canned responses
- Semantic Web crawling leveraging HTML web crawler experience
- what's attached
- what has changed
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)
- who's made that assertion – differentiate librarians from crowdsourcing
- some way to express variable confidence levels
- incorporate feedback from users
- need protocols – could leverage a
reconciliation services — not necessarily monopolies or centralized
iterative, with curation and provenance
- common API for reconciliation building on the OpenRefine API — specify as much metadata as you have, get ranked results back
mashup tools that test connections
sameAs website
- surface (publish) the results – known servers, as with annotations – select which servers to request responses or harvest data from
- notifications of new matches?
- ability to +1 or thumbs-up the connection to corroborate – Reddit gets a lot of traction that way
- repeating assertions in multiple repositories
- sameAs.org but with other expressions for and levels of confidence in the relationship
Validation
validation- RDF data shapes working group
- DCMI tutorial on RDF validation
- Measure the consistency of ontology use
- Linked data needs mashup tools that test connections and illustrate bringing data together
Ontology extension mechanisms
-query on different axes — query OCLC by VIAF id to get works
- extensions being proposed and managed on GitHub
Ability to push bookmarks
- Small
- graphs of data, consumable by others
semantic web crawling
bookmark
- , 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
a sort of Mendele but for everything
add it
- Add things to a collection I have
similar
- Similar to an annotation service
you
- You search, you refine it, you step back — now only save as bookmarks at one level
nobody
- Nobody can use your web bookmarks
2
a tool that would facilitate entity reconciliation
to put together UN and LC
a first pass, then improve that manually, then 2nd iteration
then publish — surface
manage difference of opinion
provenance
exclude some
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- now
- Hide the URIs behind a UI
Additional ideas
- Semantic autotagging
- Nanopublications – breaking academic articles into independent assertions with a mechanism to agree/disagree
- Side wikis – a plugin for the Netscape browser where a wiki could be associated with any web page and display additional, user-entered content or commentary on any web page
- 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
...
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
- works
- regular expressions to apply against EAD to suggest what is linked 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
...
- to track the number of times a link between two entities is traversed,
...
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
- effectively shortening the distance between them
- a better
...
- page rank algorithm for linked data
...
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
- anybody a favorite semantic search engine (no – too siloed)
...
- visualizations have to be crafted individually