- From: Seaborne, Andy <andy.seaborne@hp.com>
- Date: Wed, 13 Sep 2006 15:30:21 +0100
- To: Simon Raboczi <raboczi@itee.uq.edu.au>
- CC: RDF Data Access Working Group <public-rdf-dawg@w3.org>
(I'm presuming this was intended for the working group list, not he comments list. If that's wrong, I can reply on the comments list. This message is mainly tracking editorial input (do I need to track that now?) Simon Raboczi wrote: > This is my comparison of the relative merits of the current rq23 > specification [1] and its reorganized rq24 variant [2]. It's > somewhat different from Lee Feigenbaum's previous series of messages > [3][4][5] which were instead a review of rq24 itself. What I've > tried to do is describe what's moved where, and how I feel about each > of the changes. > > I'll start with the conclusion. At a structural level, rq24 is > definitely an improvement on rq23, and is a better way forward. I > don't doubt that we should adopt rq24 over rq23. The only question > in my mind is when. The reorganization process has left us with > areas in which rq24's narrative lapses entirely into @@Todo notes, > whereas rq23 is rambly but at least complete. For this reason, I'd > hesitate to say at this moment that rq24 is actually a better > document, in the sense of being the best exposition of SPARQL for the > public It certainly doesn't strike me as CR-quality. > > The key issue seems to be whether it's more important to give the > public the most polished account of SPARQL (rq23) or the most up-to- > date account of its evolution (rq24). I favor choosing the latter > and going with rq24 because I believe that the holes in it won't take > too long to patch, eliminating the only reason I see for sticking > with rq23. My ideal scenario would be for one more editoral pass to > take place before adopting rq24. At the very least, I think that > sections 1.2 and 2.5 should be either filled out or commented out, > and that the internal links broken in the course of the > reorganization should be mechanically checked and then corrected [6] > [7]. However, if the document were to drop back to WD status I feel > that immediately adopting rq24 as-is would also be acceptable. Links fixed and rq24 currently validates and passes "tidy -e". > > ----- > > Now, on to the dull details of how I actually did the comparison. I > drew myself a diagram of how the sections in rq23 were permuted to > obtain rq24. I tried to group and summarize the changes at a > meaningful level, trying to reverse engineer the editors' intentions > for the reorganization. > > * Text from the beginning of rq23.2 moved to rq24.1.2 (Document > Outline). Having an outline is a good idea, and I agree with Lee > that it belongs before the section on Document Conventions. The only > issue I take here is that another few sentences need to written to > fill out the new section and (trivially) the numbering needs to be > corrected. > > * The previous rq23.2 (Making Simple Queries) and rq23.3 (Working > with RDF Literals) received the brunt of the changes, reorganized > into four new chapters. > > * The new rq24.2 provides a series of example queries without > detailed specification. For the most most part this involved > migrating specification text elsewhere (rq23.2.1.1 through rq23.2.8) > and gathering the examples from rq23.3.1 and rq23.3.2. I think the > idea of tossing a bunch of examples at the reader right at the outset > does a lot to frame the specifications that follow later. O'Reilly > built of publishing empire on this editorial principle. :) > > * The concrete syntax of triple patterns is then specified in rq24.3, > with material drawn from rq23.2.1.1-4, and the abstract syntax and > semantics in rq24.4 with material from rq23.2.2-4 and > rq23.2.8.4-5. I personally don't think dividing the abstract and > concrete syntax into two chapters is helpful; I'd prefer to see these > two interspersed, with each individual feature's concrete and > abstract syntax treated together. Without any concrete syntax > examples, the entirety of rq24.4 is rather difficult to understand. > I'd suggest a better division would be to put the concrete and > abstract syntax details (currently rq24.3 through rq24.4.2) into > chapter 3, and the semantics of what qualifies as a solution to a > pattern (currently rq24.4.3-5) into chapter 4. This has always been an area where personal tastes differ. Some people just want the abstract definitions without syntax - the sec 3 / sec 4 split is an attempt to be like where the most people want the divide. There is a reasonable amount of syntax detail to be covered and so interspersing definitions (a bit like rq23 does) has a negative effect. We could, later, put more grammar extracts into sec 4 but it already has the key ones (triple patterns and filter). > * rq23.2.5 (Basic Graph Patterns) becomes its own chapter rq24.5. > The semantics of what qualifies as a graph solution is a pretty core > topic and certainly deserves its own chapter. I suspect there'd be > benefit in drawing in material from rq24.4.3-5 on triple pattern > solutions into this chapter, so that the entire process of filtered > basic graph pattern is in one spot. > > * I didn't note any substantial change to chapters rq23.4-6, other > than being renumbered as rq24.6-8. They have only been moved around. > * The chapters on datasets rq23.7,8,9 have been consolidated as > rq24.9 (RDF Dataset). Putting all the stuff about querying multiple > graphs at once into the one chapter seems a definite improvement. > > * The preamble to Appendix A (before the EBNF meat of it, in A.7) has > been reorganized. This seems to be a modest improvement; I don't > have any strong opinions about it. > > ----- > > My goal was to compare rq23 and rq24 rather than to proofread either > of them, but some collateral proofreading happened anyway and might > as well be captured: > > * Section rq24.1.2 appears out of sequence. > > * Section rq24.2.2 concludes with the statement "all the variables > used in the query pattern must be bound in every solution." I'm not > entirely certain this is correct; is a variable which has been > projected away (in this particular case, ?x) still bound in that > particular solution? > > * There's a forward reference to CONSTRUCT at the beginning of > rq24.2.7 which probably can't be avoided, but at least ought to be > linked to rq24.10.3 > > * EBNF fragments of the grammar appear throughout rq24.3. It would > probably help to add a link to the format used for these (XML 1.1 > section 6) in rq24.1.1 (Document Conventions) rather than (or in > addition to) the link at the beginning of rq24.A.7. (On closer > inspection, I see a @@ note in rq21.1.2 which indicates the editors > have already thought of this, although not quite in the place I > expected.) > > * The link to #syntaxMisc in section rq24.3.2 is broken: "there are > abbreviated ways of writing some common triple pattern constructs." > It might helpful to add some text noting that these abbreviations are > all adapted from Turtle, with a link. > > * The grammar rules throughout of rq24.10 are empty. I'm waiting for the grammar to be settled - the extracts are a copy so when the grammar changes, everything gets upset. I included some examples to show where it would go. So far, no one has said "does not work for me". > > * The comment just before rq24.A.1 "rules A.1 to A.5 apply" should > probably include A.6 as well. Can't find this any more. Must have got editorialized (it was in rq23 - the EBNF note went in A.7 close to use). > * A link in rq24.A.7 to #Keywords is now broken, since rq23.A.3 has > been moved to the beginning of rq24.A.7: "Matching is case-sensitive > except as noted above for keywords." Fixed. > > As a final miscellaneous observation, the section headings do not > make it easy to look up a particular keyword. It might be more > useful to name rq24.3.1.1 as "PREFIX and BASE", rq24.7 as "OPTIONAL", > rq24.9.2.1 as "FROM", rq24.10.3 as "CONSTRUCT" and so forth, or > perhaps to use longer section titles combining the keyword and > description, e.g. "Matching Alternatives using UNION". Added an @@ to do that. The timescale for publiication means it won't be done in time. > > The first paragraph of thet Abstract would fit better in rq24.1 > (Introduction). I prefer it where it is because then the intro just assumes RDF. But let's consider when the rest is done and the abstract/intro can be tuned. Andy > > ----- > > References: > [1] http://www.w3.org/2001/sw/DataAccess/rq23/ (revision 1.692) > [2] http://www.w3.org/2001/sw/DataAccess/rq23/rq24.html (revision 1.17) > [3] http://lists.w3.org/Archives/Public/public-rdf-dawg/2006JulSep/ > 0107.html > [4] http://lists.w3.org/Archives/Public/public-rdf-dawg/2006JulSep/ > 0108.html > [5] http://lists.w3.org/Archives/Public/public-rdf-dawg/2006JulSep/ > 0109.html > [6] http://www.w3.org/2001/sw/DataAccess/rq23/rq24.html#Keywords > [7] http://www.w3.org/2001/sw/DataAccess/rq23/rq24.html#syntaxMisc > > >
Received on Wednesday, 13 September 2006 14:30:48 UTC