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diff --git a/info/digests/texline/no10/acog.tex b/info/digests/texline/no10/acog.tex new file mode 100644 index 0000000000..e86008cbd8 --- /dev/null +++ b/info/digests/texline/no10/acog.tex @@ -0,0 +1,386 @@ +\centerline{\bf Idle by the Thames} +\medskip +\noindent +On April 5th--7th I had the pleasure of attending +a workshop on \sgml\ organised by the AGOCG +(Advisory Group on Computer Graphics). The reason for the +workshop ran thus: now that \sgml\ has adopted CGM (Common +Graphics Metafile) as its method of incorporating +graphics, is there a case for promoting \sgml\ as the +medium of document interchange among the graphics +community. Keen readers will notice a flaw here +straightaway: CGM is in no way a part of \sgml: on the +other hand, CALS (Computer-aided Acquisition and +Logistic Support) +does embrace both CGM and \sgml\ -- and group 4 fax, and +IGES. True, it is possible to include CGM as a `Notation'. +A `Notation' is a bit like a |\special|. You can include +anything you like, but whether anything sensible happens +to it is another matter altogether. + +As I've suggested elsewhere, in the \TeX\ world we've +been electronically interchanging documents for quite +some time. And since I'm quite convinced that \TeX\ is a +whole lot better at graphics than we admit, I thought +that it might be helpful to contribute something about +\TeX\ and\slash or graphics. (`Share experiences' as +someone said at the workshop: something to do with +changing a light bulb I think.) + +The workshop was attended my three main groups: those +presenting papers, who notionally had some grasp of +\sgml\ (this included me, so the grasp could be tenuous); +a clutch of University Computer Centre people who mostly +didn't know a document type from its declaration +(probably there for the experience); and the Rutherford +boys and girls. This last group requires a bit of +explanation: the workshop was held at the delightful +Cosener's Hall in Abingdon. Cosener's is owned\slash used +by Rutherford Labs as a sort of residential\slash +conference place. It is really delightful with an +excellent conference area, and electronic gadgetry so +advanced no-one could work it (but no email access: I was +quite twitchy after three days -- just like caffeine +deprivation). Essentially it is an outpost of Rutherford. + +The papers were, on the whole, good. Easily the best was +Tim Niblett's from the Turing Institute in Glasgow +(`\sgml\ and Programmed Documents'). I also found Angela +Scheller's paper (`Experience with \sgml\ in the real +World') very useful, since she was discussing the {\sc Daphne} +project. {\sc Daphne} (Document Application Processing in a +Heterogeneous Network Environment) uses \TeX\ as its +formatter. Hers was the only paper which demonstrated that +you could do anything with \sgml\ and CGM graphics (on her +own very particular installation). That's not quite fair, +since David Duce and Ruth Kidd of Rutherford did something +similar (`The {\sc Daphne} Document Types and AGOCG'), but +had to email it to Angela to be processed. + +Obviously there was a very heavy diet of \sgml. Paul +Ellison waded us through the murky depths of what was +happening with standards, and all the associated +standards like DSSSL, SPDL, etc, etc (`\sgml\ and related +Information Standards'). It was a rich diet of acronymns. +Martin Bryan exposed us to `Using the full power of +\sgml', an awesome prospect. + +Two things surprised me from the beginning. First was the +general low level of understanding of what was in the +various standards -- what they were for. Although all the +papers were available at least a few days in advance, +they had almost all been written for \sgml\ literate +audiences. First mistake. The second surprise was the +readiness with which standards were accepted as `a good +thing'. There was a conviction that only ISO standards +could be considered. This left \PS\ in an interesting +position, although we were assured that the SPDL +(Standard Page Description Language) would look a lot +like \PS, though without the programmability or the fonts +(what's left?). People seemed happy to accept assurances +that there would one day be suitable software to allow +\sgml\ to be input painlessly across a wide range of +platforms; that one day there would be suitable +formatters linked to the \sgml\ to allow you to see what +had been input to \sgml; and that one day there would be +enough DTDs (Document Type Definitions: broadly +analagous to \LaTeX\ styles) to suit a reasonable range of +needs. + +The workshop convenor, Anne Mumford, made it clear from +the start that we were supposed to work for our living +and make some recommendations about electronic document +interchange. Most of the papers and discussion addressed +this in a general way (although I would argue that only +three of the dozen or so invited papers even +{\it considered\/} graphics at all -- mine, and the two +{\sc Daphne} papers). I had understood the `community' to +be the academic\slash research community (hence the +inclusion, for example, of Lou Burnard and TEI -- the Text +Encoding Initiative). However, it never did become very +clear exactly who the `community' were supposed to be. + +To focus our minds, Anne had +distributed a list of `discussion topics': +\item{\rtr}what requirements does the community have for +document exchange? +\item{\rtr}what are the target systems? +\item{\rtr}what document types meed to be defined for the +community? +\item{\rtr}what software can we use today? +\item{\rtr}what software do we need to have available if +\sgml\ is to be a successful form of document interchange? +\item{\rtr}what support is needed in the community if we are +to move to use \sgml? +\item{\rtr}writing funding proposals for the community for +work to get \sgml\ in use. + +\noindent +It was fairly clear from these topics that at best we +could bring in a verdict of `not proven' for \sgml's +suitability, but there was no way we could reject it +entirely. The whole jury was biassed towards one view +point. To ensure `evenhandedness', an extra speaker +(Ian Campbell-Smith of ICL) was shipped in at the last +minute to tell us something about ODA (note that the `O' +now implies `Open', not `Office' as it once did). + +But eventually, when the work came to be done, these +topics were laid aside and the real reason for the workshop +appeared. The participants were broken into three groups. +I should have sensed something was wrong when two of the +groups were to be chaired by Rutherford people (the other +by the convenor): I definitely realised that we had been +railroaded when a revised sheet of topics +appeared to be considered by each group. True, these +revised topics could be considered to have arisen during +the course of the workshop: however they were not logical +outgrowths of either the explicit purpose of the workshop, +nor of the main direction of discussion. So replace those discussion +topics given above with: + +\noindent ``AGOCG wishes to distribute: +\item{\rtr}viewgraphs +\item{\rtr}teaching material +\item{\rtr}manuals + +\noindent to University sites in a form where they can +incorporate it into local teaching material and +documentation. +\item{\rtr}is \sgml\ the right protocol to use? +\item{\rtr}if so, are the {\sc Daphne} DTDs a good starting +point? +\item{\rtr}if so, what changes are needed? +\item{\rtr}are there commercial offerings we should consider? +\item{\rtr}what utilities related to the \sgml\ system are +needed? +\item{\rtr}should the UK academic community develop its own +software? +\item{\rtr}how should what AGOCG does be influenced by other +requirements? +\item{\rtr}if we target for {\tt troff} and \TeX\ is that +sufficient?'' + +\noindent If the conclusions had been pre-empted before, +they were even more constrained now! + +As Bob Hopgood of Rutherford explained, the question {\it he} +wanted answered could be summarised `how can Rutherford best +distribute the GKS manual electronically'. That was why {\it +he} had brought us together, and why {\it he} had had the workshop +organised (the myth of ACOCG as an entity with any existence +outside Hopgood was eliminated). Plain and simple. Had that been +an explicit question from the outset we could have given him an +answer on day one and then got down to something more +interesting. Given Hopgood's position at Rutherford, the +weighting of the workshop and its work groups towards +Rutherford, and the master stroke of a piece of paper with +specific questions, it was inevitable that it was difficult to +restore the workshop to its apparent explicit purpose. + +An interesting by-product of the workshop was the +prepared papers. They illustrated neatly the problem +with systems which emphasise structure and virtually +ignore formatting: they may have been logically +structured, but in terms of document design they were +almost uniformly appalling, and difficult to read: the +typewriter conventions of underlining, no indentation on +the first line of a paragraph, but an extra `line' between +paragraphs, and so on were much in evidence. Even +`standard' \LaTeX\ documents were starting to look +well-designed by comparison. + +That does not mean the workshop was a waste of time. From +my own point of view it helped me put straight my view of +\TeX\ and graphics; it allowed me to raise the perennial +question of the character corruption which occurs to file +transfers which pass through the Rutherford Gateway (and +to be told that it was because I was trying to pass +`non-mail' characters through -- whatever that +mumbo-jumbo means); it revealed the immense ignorance +that persists about \sgml, ODA, \TeX, and practically +everything else we've been doing for the last five to ten +years. Yes it depressed me -- especially the ready +adherence to tomorrow's software in preference to today's +tested and available software. But the food was +plentiful, the majority of the participants stimulating, +and the surroundings extremely pleasant. If only it had +been a bit more rigorous. Beware Rutherford Appleton Labs +bearing gifts! + + +\rightline{\sl \mwc} + +\bar\centerline{\bf Echoes} +\smallskip +\noindent +The Displays Group of the BCS held a `State of the Art +Seminar' on Systems Integration and Data Exchange on +February 28th. This meeting examined some of the current +range of `documentation' standards like \sgml, ODA, CGM, +\PS\ and CALS. It was curious that this came so hot on +the heels of the BCS Electronic Publishing Group's +similar one day meeting. Much could be gained by a little +more cooperation here. Nevertheless, outside the subject +matter there was surprisingly little overlap. The speakers were +different, and the audience was not the same as the EP one +(except for me, I think). + +One of the things I found interesting was the +re-usability of presentations. One of the major selling +points for \sgml\ is that it allows the same information +to be re-used in a number of forms. In fact, if you are +not going to re-use the information, it becomes difficult +to justify the added inconvenience of \sgml. Paul +Ellison's talk was re-used at the AGOCG Workshop the +following week; Alan Francis' presentation was a +reworking of his Electronic Publishing talk at Durham +last year (and at the AGOCG meeting I heard Lou Burnard +re-present the paper he had given at the BCS ep meeting). +It often helps to hear the same material again -- the +army principle of `tell them what you're going to tell +them; tell them it; and then tell them what it is they've +just heard'. Even Heather Brown's talk reminded me of +something I had once heard at another Displays Group +meeting at Rutherford Labs. All a case of d\'j\`a \'ecout\'e. + +Anne Mumford (Integration and Exchange -- +Restating the Case for Standards) introduced the day by +making a case for standards. Here standards tend to be +taken to mean `Standards, as agreed and ratified by +national or international bodies'. + +Paul Ellison (\sgml\ and Related Information Standards) +led us through the many-threaded path of `\sgml\ and +Related Information Standards', and even treated us to his +version of how Adobe was led to the sacrificial altar to place +\PS\ `in the public domain'. I'd heard a rather different +version, so it will be interesting to find out just what +went on. There must be room for a book on Adobe, just like +the clutch of books which have come out recently on Apple. +It is difficult to get excited about the many standards and +what seems like their interminably slow path to acceptance. + +One of Paul's claims was that math coding through \sgml\ +would mean that the resultant formulas could be input to +algebraic manipulation systems. This seemed such a very +useful attribute that I contacted Barbara Beeton to see +if she knew of any cases where this was done. She was +unable to uncover anything. On the other hand, several +systems, Mathematica included, output \TeX\ form +formulas. This tendency to attribute to \sgml\ +capabilities which only exist in theory does worry me. I +would like to see something substantive. + +Heather Brown's talk (Structured Multimedia Documents and +the Office ({\it sic\/}!) Document Architecture) was a very +good overview of ODA -- easily the best I've heard so far. +It is quite intriguing how both \sgml\ and ODA appear to be +embracing `multimedia'. ODA almost offers something which +I find quite interesting (something that \TeX\slash +\LaTeX\ offers too, but have failed to +point out to the world as a positive feature). An +ODA document can be revisable or not: depending on what +you ship, the recipient can change it and reformat it, or +merely print it out (in \TeX\ terms you can send the +marked up text, which is revisable, or the \dvi, which +isn't). There are many documents which you do not wish to +be changed. The ultimate non-revisable document must be +the fax, but it's usually also unreadable. It seems to me +that ODA is a little more realistic than \sgml\ in its +world view. It at least acknowledges that there is a +layout structure, as well as a logical one. + +Alan Francis discussed the many differences between CGM +and \PS\ (CGM versus \PS\ -- Horses for Courses). It should +come as no real surprise that they are trying to address +slightly different issues, and that in different +circumstances one is more applicable than the other. Since +CGM isn't a programming language and doesn't address +itself to font questions, it is a great deal simpler and +more compact. Converting from CGM to \PS\ seems no great +feat. CGM is undoubtedly an ideal way of encoding graphics +for interchange. I note that there are some \dvi\ drivers +which can accept included CGM, and also that +Wilcox's Metaplot may also convert CGM to \MF. As usual, +we're there, but we aren't jumping up and down about it. It +seemed to me less a case of horses for courses than +of trying to compare bicycles and fish. + +Jon Owen (Standards for Product Data Exchange +and Conformance Testing) illustrated that exchanging +CAD-CAM graphics and diagrams was certainly possible, but +that you had to be very careful to establish just what it +was you thought you were exchanging. The drawings didn't +always contain all the information you expected: the old +adage about what you see not being all there is, far less +what you want, was brought home very clearly. + +In a multi-authored paper from Rutherford Labs, (Integration +of Graphics and Communications in {\sc Argosi}: J Gollop, +R Day, R Maybury \& D A Duce) Duce looked at {\sc Argosi}, a +`European' project to transmit continuously updated +information to selected points. {\sc Argosi} (Applications +Related Graphics and OSI Standards Integration) is an +Esprit project to advance the state of the art of +communicating graphical information over international +networks. The specific demonstrator application chosen is +a prototype road freight scheduling system, calling on +databases in nations represented in the project. The +databases contain causes of delay which a freight +scheduler needs to take into account when planning a +Europe-wide journey. + +Lastly, Norman Harris of Procad described the CALS +project (CALS -- the US Initiative). With the massive +backing of the DoD (and now a number of other US Government +agencies) CALS has lent massive legitimacy to \sgml, having +`adopted' it as one of its many `standards'. I have a +sneaky suspicion that CALS has managed to rescue \sgml\ +from the doldrums. Harris described some of the original +motivation and history of the iniative, covering TIMS and +ATOS. As I have commented elsewhere, one of the curious +by-products of CALS may be to save trees, since one +objective is to reduce the paper flows between and within +the contractors and the military. CALS will have a very +wide effect: besides the US Armed Forces, other Armed +Forces may adopt it; non-US aerospace and `defence' +contractors will have to comply to tender for US +contracts; some CALS specifications have been proposed as +FIPS (Federal Information Processing Standards) for use +throughout the US federal government. Some state +governments (especially those like California and +Washington with a large number of arms contractors) are +likely to adopt it. CALS is not static, and the next +stages include examination of other `interchange' formats +and standards, like ODA/ODIF, SQL (Structured Query +Language), and PDES (Product Data Exchange Specification). + +The absence of the last speaker meant that there was extra +time for discussion. The printed version of this paper by +Shiela Lewis (Testing, Testing, One, Two, Three) raised +several interesting issues about conformance testing, +chiefly in the context of the CALS Test Network. At a +time when many vendors claim to adhere to various +standards, it is valuable to see what mechanisms are +being invoked to clarify what adherance means. She notes +that `Conformance testing does not in any way prove the +usability of the product, simply its ability to process +code in the manner prescribed by the Standard'. + +An interesting programme which would have been a worthy +BCS ep meeting -- it seems a great pity that there is not +greater coordination between the groups. Calling it a +`State of the Art Seminar' was very astute! It seemed a bit +expensive to me, especially as there were no +foreign speakers jetted in at enormous cost, and no lunch. +BCS ep provides speakers of equivalent standard (sometimes +the same ones!), and lunch. The only advantage that I +would say this meeting had was the provision of the papers +to all the participants. I have mixed feelings about this: +on the one hand it is a real boon to the audience (and to a +reviewer). On the other hand it puts sufficient extra work +into the hands of the speakers that it might dissuade some +of them from speaking at all. + +\rightline{\sl Malcolm Clark} |