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Re: "Completeness" as a feature of a POW (aka EPUB+Web)??

From: Bill McCoy <bmccoy@idpf.org>
Date: Thu, 13 Aug 2015 12:00:39 -0700
Message-ID: <CADMjS0Y2Pp3+rU5qhACbzzRt=SZTYPc+9NhvcLzqjBA-cQ3bHA@mail.gmail.com>
To: Leonard Rosenthol <lrosenth@adobe.com>
Cc: Bill Kasdorf <bkasdorf@apexcovantage.com>, Ivan Herman <ivan@w3.org>, W3C Digital Publishing IG <public-digipub-ig@w3.org>
I agree with Leonard that this is not black and white.

But maybe it would be helpful to tease apart the concepts of "portable"
from "document"/"publication"... it might be interesting to consider
whether there is anything that distinguishes app-ness from document-ness
independent of the vector of portability and what that implies for the
nature of dynamic content embedded within a publication. My "idempotency"
suggestion (and like Ivan I don't necessarily believe this is the best
term, I was just searching for something to concisely capture the
resource=representation constraint vs. full REST architecture) is really
not about document-ness it's about portability. It could, perhaps, be
considered to have some relation to "publication" if the verb sense of that
word is implied (i.e. a "publication" could be distinguished from a
"document" by the act of publishing, which has a significance in re:

Anyway I believe we can in principle have portable apps as well as portable
documents.. For a counter-example, the biggest showcase for "HTML5" - at
least in the eyes of my 12-year-old - is agar.io, something that in the
past would have required Flash or a native app but now he can play on any
device that has a browser. But all the logic of agar.io is on the server
side, the client side seems to a rather dumb pipe... it's a credit to OWP
that it can be responsive enough for this MMOG but it would be rather
senseless to imagine archiving it so it is in no sense a "portable" app
experience. OTOH one could in principle imagine a radically different
version of agar.io where all the logic was client-side and you could play
offline against bots and, perhaps, optionally online against humans... aka
it would be portable..

So I think that a fully portable document/publication should be expected to
have the transitive property of portability. That is to say, all its
components (like quizzes) should themselves be portable. The less this is
true the less we can consider the overall publication to be a portable
document and the more it is a website (i.e. full REST architecture,
including that resources are != representations).

Caching to me is a tricky thing to try to mix in to this taxonomy. A cache
is a temporally-limited thing, and one which may not always be accurate...
i.e. it is not absolutely guaranteed that the cached representation
previously returned by a resource is identical to the representation that
would be provided in answer to a new request. Fundamentally the role of
HTTP caching is to optimize real-time network throughput not to make
permanent promises about the nature of the content... and browser caching
in particular has many tricky aspects. I think one reason the original
HTML5 offline support got into trouble was its attempt to build on the
browser cache.


On Thu, Aug 13, 2015 at 11:29 AM, Leonard Rosenthol <lrosenth@adobe.com>

> I think the second case - dynamic content - is not as clear cut as you
> make it out to be, Bill.  It is very dependent on how that information is
> presented - or how much of the publication’s “content” is actually derived
> from that data.
> Sure, if we are only talking about a single value on a page (such as a
> stock price or the current weather), not having it probably wouldn’t impact
> the understanding of the material or the consumption experience of the
> publication.  BUT consider something such as an embedded quiz in a
> textbook, where the questions themselves are coming in live…if they aren’t
> available (either live or cached) then the student can’t continue..
> Leonard
> On 8/13/15, 11:38 AM, "Bill Kasdorf" <bkasdorf@apexcovantage.com> wrote:
> >Just a quick observation wrt Ivan's example of citations to external
> publications (my deliberate wording). The papers cited in a journal article
> (often scores and sometimes hundreds of them) are NOT part of "the
> publication," they are referenced by the publication. The citations are
> part of the publication; the cited resources are not.
> >
> >We need to be careful, in considering the concept of completeness, to
> distinguish between whether we are talking about "the publication itself"
> vs. "the publication and everything else it references."
> >
> >This also applies to dynamic content, e.g., a link that fetches
> up-to-date information (a stock price, the weather in Sydney, comments from
> other students in my class on what we're studying, etc.).
> >
> >In both of those cases, imo, it is reasonable to consider the publication
> complete (and, put the other way around, inappropriate to consider it
> incomplete) if those links/citations are present, even if they are not
> actionable at a given time (e.g., when the portable version of the
> publication is consumed offline), and whether or not the external content
> has been cached. This is _very_ important for publications like magazines
> and news publications. (Be careful to avoid reflexively thinking "books.")
> >
> >--Bill K
> >
> >-----Original Message-----
> >From: Ivan Herman [mailto:ivan@w3.org]
> >Sent: Thursday, August 13, 2015 12:55 AM
> >To: Leonard Rosenthol
> >Cc: W3C Digital Publishing IG; Bill McCoy
> >Subject: Re: "Completeness" as a feature of a POW (aka EPUB+Web)??
> >
> >Leonard,
> >
> >good catch, the formulation is indeed not clear. Obviously, there is a
> need for external link to various things; to take the area of academic
> publication as an example, such a publication may include references to
> other papers, it may include references to research data (that may be too
> large to be included in the document), etc, and it is essential to keep the
> hyperlink nature of those references. In this sense, "completeness" is not
> meant to be "fully self-contained".
> >
> >I think that Bill's answer[1]:
> >
> >"portable documents "promise" a reliable consumption experience without
> respect of any particular server infrastructure and, especially, without
> such server infrastructure providing interactivity."
> >
> >what I believe we all mean. I am not sure "idempotence"[2], proposed by
> Bill, is really the right term, but I do not have a better one at this
> point either:-(
> >
> >Thanks
> >
> >Ivan
> >
> >[1]
> https://lists.w3.org/Archives/Public/public-digipub-ig/2015Aug/0056.html
> >[2] https://en.wikipedia.org/wiki/Idempotence
> >
> >
> >> On 13 Aug 2015, at 02:31 , Leonard Rosenthol <lrosenth@adobe.com>
> wrote:
> >>
> >> In rewriting the document about Portable Documents for the web (thanks
> for the suggestion & link, Tzviya), I can across the following paragraph:
> >>
> >>> EPUB can be viewed as simply defining a specialization of Web content
> that assures that a collection of content items has the needed properties
> of completeness and logical structure, and does so in a standard way that
> other processing tools and services can reliably create, manipulate, and
> present such collections. This completeness constraint is key for bridging
> the current gap between an online and offline/portable view of the same
> content (see <a href="#whynow">section on usage patterns</a> below).
> >>>
> >> While not spelled out here or in the “section on usage patterns”, I am
> going to take the terminology of “completeness” to mean “fully
> self-contained” (aka no external references).  If it means something else,
> feel free to ignore what follows (but only after you correct me :).
> >>
> >> In the current use cases for EPUB (books, magazines, etc.), the desire
> by the publisher to have everything contained inside the package is clearly
> key – just as that same property has been a tenant of the various PDF
> subset standards (PDF/A, PDF/X, etc.)  However, there also exists for PDF
> use cases where external references are a key aspect to the workflow – for
> example, external content or color profiles in a variable or transactional
> workflow (eg. PDF/VT).   As such, I would like to suggest that as a
> portable document for OWP, that there also needs to be a provision for
> external references in this POW (Portable Open Web) format.
> >>
> >> I know that there have been discussions about this around EPUB in the
> past for large assets (eg. Video and audio), but I would put forth that the
> same principles could also be applied for other types of content as well.
> Be it advertisements in a publication, current data sets in a STEM
> publication or even just a reference to the latest version of a common JS
> library used by the publication.
> >>
> >> What do others think about this?   Is completeness/self-contained a
> requirement in a POW?
> >>
> >> Thanks,
> >> Leonard
> >>
> >
> >
> >----
> >Ivan Herman, W3C
> >Digital Publishing Activity Lead
> >Home: http://www.w3.org/People/Ivan/
> >mobile: +31-641044153
> >ORCID ID: http://orcid.org/0000-0003-0782-2704
> >
> >
> >
> >
Received on Thursday, 13 August 2015 19:01:31 UTC

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