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Ross,

our use case is not only modeling and storing domain data as RDF and
publishing it as Linked Data (regardless of the domain), but also
modeling the web application layer as RDF/OWL.

We have developed a completely new declarative webapp architecture,
where a generic processor executes app-specific ontologies which
encapsulate the business logic in terms of SPARQL queries, URI
templates, XSLT stylesheets etc. Using this approach, no imperative
source code such as Java needs to be written in order to build Linked
Data applications. That will make a great difference in the long term.

For a technical description, you can see our SWAT4LS paper:
http://ceur-ws.org/Vol-1320/paper_30.pdf

Martynas
graphityhq.com

On Fri, Apr 17, 2015 at 9:09 AM, Ross Singer <[log in to unmask]> wrote:
> Martynas,
>
> I don't think I've tried to present it otherwise.  We *want* the data layer
> to be a silo, honestly - we use the application layer to expose the linked
> data.  Of the list of things our customers care about, a SPARQL endpoint is
> fairly near the bottom: yes, it's been asked for, but to be honest, those
> customers crawl their linked data and put it in their own triple store (or
> *whatever*), anyway, so it's a pretty low priority (compared to other
> requests) even for them.
>
> Our architecture also works orders of magnitude better than triple stores
> did for our use cases, and I can't figure out your objection to that,
> honestly.
>
> What's *your* use case, exactly?
> -Ross.
>
> On Fri, Apr 17, 2015 at 1:22 AM Martynas Jusevičius <[log in to unmask]>
> wrote:
>>
>> Ross,
>>
>> in this case you're operating a good old data silo, with an RDF export
>> capability.
>>
>> Besides solving the integration issue, RDF also opens a way to
>> gradually move business rules and user interaction logic from
>> (imperative) code to (declarative) data. It enables new generic
>> software design patterns, which I hesitated to go into on this list.
>> But you can take a look at our SWAT4LS about Graphity platform
>> architecture:
>> http://ceur-ws.org/Vol-1320/paper_30.pdf
>>
>> Martynas
>>
>> On Tue, Apr 14, 2015 at 9:21 AM, Ross Singer <[log in to unmask]>
>> wrote:
>> > Martynas,
>> >
>> > You have to understand, *we abandoned using a triple store after using
>> > one
>> > for many years*. Advancing RDF and Linked Data was the primary tenet of
>> > the
>> > company and everything we produced used the triple store in some
>> > capacity.
>> > This wasn't an issue of not understanding RDF or not having used SPARQL
>> > in
>> > anger.
>> >
>> > But in the end we abandoned using a native triple store because the
>> > things
>> > that they're good at: storing and retrieving data from various sources
>> > with
>> > unbounded shapes and performing ad hoc queries on it accounted for less
>> > than
>> > 1% of our use cases.
>> >
>> > For the other 99%, triple stores proved inefficient and awkward and
>> > required
>> > far more operational scaffolding to scale.
>> >
>> > To answer your question about querying our data, we pre-compute the vast
>> > majority of our common joins into multi-describe graphs, somewhat
>> > analogous
>> > to a RDBMS view. We also pre-compute tabular data out of the graphs for
>> > SPARQL select-like functionality. The rest we can just query in Mongo,
>> > if we
>> > wanted, but we rarely have a need to (tracking down a support problem,
>> > maybe). It does not support SPARQL, no. There's no use case for it.
>> >
>> > The point is that our data is all modeled to ingest and export RDF
>> > quads, so
>> > we're not locked into anything and when we need to run ad hoc queries,
>> > we
>> > can ingest our data into a Fuseki instance we run: but that's for a
>> > specific
>> > need, which is completely different than the general workflow and
>> > operation
>> > of everything else.
>> >
>> > -Ross.
>> >
>> >
>> > On Monday, April 13, 2015, Martynas Jusevičius <[log in to unmask]>
>> > wrote:
>> >>
>> >> Ross,
>> >>
>> >> I wonder how you query your MongoDB store? I don't suppose it supports
>> >> SPARQL?
>> >>
>> >> On Mon, Apr 13, 2015 at 11:51 PM, Ross Singer <[log in to unmask]>
>> >> wrote:
>> >> > Kelley,
>> >> >
>> >> > I stick by the notion that as long as a system can ingest/export data
>> >> > as
>> >> > well-formed RDF graphs, how you store it internally makes no
>> >> > difference.
>> >> > As
>> >> > I've said before, our biggest product is modeled entirely using RDF,
>> >> > but
>> >> > we
>> >> > store the data in a MongoDB document database, because it fits our
>> >> > actual
>> >> > needs better than a triple store.
>> >> >
>> >> > It is possible, btw, to produce an ordered list for author/editor
>> >> > names
>> >> > in
>> >> > RDF, but it's horribly ugly: you can use rdf:Seq
>> >> > http://www.w3.org/TR/rdf-schema/#ch_seq or rdf:List
>> >> > http://www.w3.org/TR/rdf-schema/#ch_list.  They each have their
>> >> > pluses
>> >> > and
>> >> > minuses: rdf:List is absolutely awful to work with in any
>> >> > serialization
>> >> > except Turtle (where it's super easy! see:
>> >> > http://www.w3.org/2007/02/turtle/primer/#L2986), but has the downside
>> >> > of
>> >> > being semantically open.  That is, you cannot definitively say "these
>> >> > are
>> >> > *all* of the authors and there are no more".
>> >> >
>> >> > rdf:Seq (which is an rdf:Container) is considered closed (i.e. there
>> >> > is
>> >> > no
>> >> > assumption that there would be anything else in the current container
>> >> > that
>> >> > appears somewhere else) but, unfortunately has no syntactic sugar
>> >> > like
>> >> > Collections in Turtle.
>> >> >
>> >> > Containers and Collections being such major pain points in RDF,
>> >> > JSON-LD
>> >> > threw all of it away for a *much* simpler implementation:
>> >> > http://www.w3.org/TR/json-ld/#sets-and-lists
>> >> >
>> >> > All that said, as long as you can serialize your author lists as one
>> >> > of
>> >> > these, model it however suits your needs the best for your regular
>> >> > workflows/needs.
>> >> >
>> >> > -Ross.
>> >> >
>> >> > On Mon, Apr 13, 2015 at 6:12 AM Kelley McGrath <[log in to unmask]>
>> >> > wrote:
>> >> >>
>> >> >> Although much of the discussion on storing bibframe data went over
>> >> >> my
>> >> >> head, some things have been niggling at me for a while that maybe
>> >> >> are
>> >> >> related to this thread.
>> >> >>
>> >> >> I get that it would be good for us to publish our data as linked
>> >> >> data.
>> >> >> I
>> >> >> get that it would be good for us to consume linked data. I get that
>> >> >> we
>> >> >> should re-use other people's URIs in our data to save time and
>> >> >> reduce
>> >> >> maintenance. I get that we should match our identifiers to other
>> >> >> people's
>> >> >> URIs in order to connect more information.
>> >> >>
>> >> >> However, it has not been clear to me that it makes sense for us to
>> >> >> store
>> >> >> and maintain our data as linked data. And yet, I don't see any
>> >> >> alternative
>> >> >> plan being developed.
>> >> >>
>> >> >> This may be sacrilege, but from what I understand there seem to be
>> >> >> things
>> >> >> that linked data isn't good at. For example, retaining the order of
>> >> >> things
>> >> >> like authors' names or connecting a specific place and publisher
>> >> >> written on
>> >> >> the title page or a book. Sometimes when this has been discussed on
>> >> >> this
>> >> >> list, I get the impression that we shouldn't want to do those
>> >> >> things;
>> >> >> that
>> >> >> they're somehow obsolete.
>> >> >>
>> >> >> I can't get my head around that. Maybe you don't need those things
>> >> >> for
>> >> >> linking, but I don't think linking is the only thing that we want to
>> >> >> do
>> >> >> with
>> >> >> our data. For example, it emerged recently, when MPOW changed to a
>> >> >> discovery
>> >> >> layer that didn't do such a good job with this initially, that the
>> >> >> ability
>> >> >> to generate citations is hugely important to a significant portion
>> >> >> of
>> >> >> our
>> >> >> patrons. If you want to generate an accurate citation, you need to
>> >> >> know
>> >> >> the
>> >> >> order of the author's names.
>> >> >>
>> >> >> It has been suggested to me that we shouldn't be generating
>> >> >> citations,
>> >> >> but
>> >> >> rather storing them as strings. However, again I seem to be missing
>> >> >> something because that doesn't seem very optimal to me. Do you store
>> >> >> a
>> >> >> separate string for every format: APA, MLA, Chicago, etc.? What do
>> >> >> you
>> >> >> do
>> >> >> when a style guide gets updated? It might not be very easy to update
>> >> >> millions of strings. What if a new citation style is invented and
>> >> >> becomes
>> >> >> popular? It just seems to me to be more flexible and powerful to
>> >> >> store
>> >> >> the
>> >> >> individual pieces of data and generate the citations. On the other
>> >> >> hand,
>> >> >> publishing citations as strings might be okay for most use cases.
>> >> >>
>> >> >> MARC records are a single unit. If a record has been edited by
>> >> >> multiple
>> >> >> parties, you can't tell who changed what when, which is a challenge
>> >> >> for
>> >> >> trouble-shooting and quality control. Linked data statements are
>> >> >> atomistic,
>> >> >> but it sounds to me like it is still hard to say anything much
>> >> >> *about*
>> >> >> the
>> >> >> statement other than maybe the domain name used by whoever made it.
>> >> >> It
>> >> >> would
>> >> >> be useful to track more about individual statements, such as when
>> >> >> they
>> >> >> are
>> >> >> made and whether or not they are currently considered valid (one of
>> >> >> the
>> >> >> problems with bad data in the OCLC master record environment is that
>> >> >> even if
>> >> >> you take erroneous information out, all it takes is one batchload to
>> >> >> put it
>> >> >> right back in).
>> >> >>
>> >> >> As some of you know, I have been working on a project to crowdsource
>> >> >> the
>> >> >> parsing of film credits in catalog records (help us out at
>> >> >> http://olac-annotator.org/ ). One result of this is that we have
>> >> >> links
>> >> >> between transcribed names in records and their authorized form.  It
>> >> >> occurs
>> >> >> to me that this might be a useful thing to record proactively. For
>> >> >> example,
>> >> >> even in a world of identifiers, we still need to choose one of many
>> >> >> possible
>> >> >> versions of a name to display to the user (unless you're going to
>> >> >> display
>> >> >> them all at once in some kind of cluster, which is not very
>> >> >> user-friendly in
>> >> >> many situations). In library cataloging, traditionally, for people
>> >> >> the
>> >> >> most
>> >> >> common or the most recent variation is chosen as the preferred one.
>> >> >> However,
>> >> >> if the math changes, you have to wait for a person with NACO powers
>> >> >> to
>> >> >> notice this and fix it. This doesn't always happen in a timely
>> >> >> fashion.
>> >> >> In
>> >> >> his earliest movies, Laurence Fishburne was credited as Larry
>> >> >> Fishburne
>> >> >> so
>> >> >> this is how his name was established. It then persisted in library
>> >> >> catalogs
>> >> >> as Larry Fishburne for long, long after after he made the change (I
>> >> >> think
>> >> >> ten years) . If you had data like this, the computer could do the
>> >> >> math
>> >> >> and
>> >> >> display the most current form.
>> >> >>
>> >> >> Name on piece   Year and work
>> >> >> Larry Fishburne 1984    The Cotton Club
>> >> >> Larry Fishburne         1985    The Color Purple
>> >> >> Laurence Fishburne      1993    Searching for Bobby Fischer
>> >> >> Laurence Fishburne      1999    The Matrix
>> >> >> Laurence Fishburne      2006    Mission: Impossible III
>> >> >>
>> >> >> (if you look at IMDb's Laurence Fishburne page, they do track all
>> >> >> this,
>> >> >> along with the names of the characters he played:
>> >> >> http://www.imdb.com/name/nm0000401/ )
>> >> >>
>> >> >> With linked data, you can say
>> >> >>
>> >> >> Movie1  -- has actor  -- LF123
>> >> >> Movie1 -- has actor's name credited as  -- "Laurence Fishburne"
>> >> >> LF123  -- has been credited as -- "Laurence Fishburne"
>> >> >>
>> >> >> But you can't get all three of those things to connect up, at least
>> >> >> not
>> >> >> without using blank nodes, which then makes your data not so
>> >> >> shareable.
>> >> >> So
>> >> >> far as I can see, anytime you want to connect the dots between more
>> >> >> than two
>> >> >> pieces of information or say something about a statement, it doesn't
>> >> >> work so
>> >> >> well with triples. This might not be such a problem for linking, but
>> >> >> I
>> >> >> think
>> >> >> there are other things we want to do with our data where we may want
>> >> >> this
>> >> >> ability.
>> >> >>
>> >> >> What happens if we implement bibframe and we don't store and
>> >> >> maintain
>> >> >> our
>> >> >> data as bibframe triples? We could just keep generating bibframe
>> >> >> from
>> >> >> MARC
>> >> >> records, but then we haven't really replaced MARC or gotten more
>> >> >> flexible,
>> >> >> structured data than we already have.
>> >> >>
>> >> >> Alternatively, ILS vendors could come up with another internal
>> >> >> format
>> >> >> for
>> >> >> us to store data in. However, I don't know that they have the right
>> >> >> expertise for this nor any economic incentives. If this happened, we
>> >> >> would
>> >> >> also end up with much less portable data. Imagine if bib records
>> >> >> were
>> >> >> like
>> >> >> item records and every system had its proprietary format and unique
>> >> >> combination of fields. Anytime you do an ILS migration, there is a
>> >> >> lot
>> >> >> of
>> >> >> item data that can't be moved to the new system, either because it's
>> >> >> structured differently or because there is no equivalent field.
>> >> >>
>> >> >> This may be completely wrong-headed and I think I'm using the wrong
>> >> >> vocabulary some places, but I thought I'd throw it out there in case
>> >> >> someone
>> >> >> can enlighten me.
>> >> >>
>> >> >> Kelley