- From: Jason Douglas <jasondouglas@google.com>
- Date: Tue, 25 Mar 2014 16:08:01 +0000
- To: Pat Hayes <phayes@ihmc.us>, Markus Lanthaler <markus.lanthaler@gmx.net>
- Cc: public-hydra@w3.org, public-lod@w3.org, W3C Web Schemas Task Force <public-vocabs@w3.org>
- Message-ID: <CAEiKvUABR4kXQBQMbCjiNTK3gqBD_KYGkeD1uVcBNX3X97kzhw@mail.gmail.com>
I find that so awkward since :knows is already a repeated property. Now we have denormalized semantics and queries have to look at both properties... and the only gain is the metadata about pagination. That's why I prefer an orthogonal mechanism like knows/collection for just the metadata. On Tue Mar 25 2014 at 9:01:33 AM, Pat Hayes <phayes@ihmc.us> wrote: > Seems to me that the, um, mistake that is made here is to use the same > property schema:knows for both the individual case and the list case. Why > not invent a new property for the list case, say :knowsList, and add a > relationship between them as an RDF triple: > > :knowsList :listPropertyOf schema:knows . > > where :listPropertyOf has the semantic condition > > aaa listPropertyOf bbb > xxx aaa ddd > ddd schema:itemLIstElement yyy > > imply > > xxx bbb yyy > > Which can be published as a reference in the home document for the URL for > :listPropertyOf , but implemented by whatever code anyone finds handy. > > Pat Hayes > > On Mar 24, 2014, at 10:24 AM, Markus Lanthaler <markus.lanthaler@gmx.net> > wrote: > > > Hi all, > > > > We have an interesting discussion in the Hydra W3C Community Group [1] > > regarding collections and would like to hear more opinions and ideas. I'm > > sure this is an issue a lot of Linked Data applications face in practice. > > > > Let's assume we want to build a Web API that exposes information about > > persons and their friends. Using schema.org, your data would look > somewhat > > like this: > > > > </markus> a schema:Person ; > > schema:knows </alice> ; > > ... > > schema:knows </zorro> . > > > > All this information would be available in the document at /markus > (please > > let's not talk about hash URLs etc. here, ok?). Depending on the number > of > > friends, the document however may grow too large. Web APIs typically > solve > > that by introducing an intermediary (paged) resource such as > > /markus/friends/. In Schema.org we have ItemList to do so: > > > > </markus> a schema:Person ; > > schema:knows </markus/friends/> . > > > > </markus/friends/> a schema:ItemList ; > > schema:itemListElement </alice> ; > > ... > > schema: itemListElement </zorro> . > > > > This works, but has two problems: > > 1) it breaks the /markus --[knows]--> /alice relationship > > 2) it says that /markus --[knows]--> /markus/friends > > > > While 1) can easily be fixed, 2) is much trickier--especially if we > consider > > cases that don't use schema.org with its "weak semantics" but a > vocabulary > > that uses rdfs:range, such as FOAF. In that case, the statement > > > > </markus> foaf:knows </markus/friends/> . > > > > and the fact that > > > > foaf:knows rdfs:range foaf:Person . > > > > would yield to the "wrong" inference that /markus/friends is a > foaf:Person. > > > > How do you deal with such cases? > > > > How is schema.org intended to be used in cases like these? Is the above > use > > of ItemList sensible or is this something that should better be avoided? > > > > > > Thanks, > > Markus > > > > > > P.S.: I'm aware of how LDP handles this issue, but, while I generally > like > > the approach it takes, I don't like that fact that it imposes a specific > > interaction model. > > > > > > [1] http://bit.ly/HydraCG > > > > > > > > -- > > Markus Lanthaler > > @markuslanthaler > > > > > > > > > > > > > > ------------------------------------------------------------ > IHMC (850)434 8903 home > 40 South Alcaniz St. (850)202 4416 office > Pensacola (850)202 4440 fax > FL 32502 (850)291 0667 mobile (preferred) > phayes@ihmc.us http://www.ihmc.us/users/phayes > > > > > > > >
Received on Tuesday, 25 March 2014 16:08:36 UTC