How to cite this paper

Sperberg-McQueen, C. M. “Opening up and closing down.” Presented at Balisage: The Markup Conference 2011, Montréal, Canada, August 2 - 5, 2011. In Proceedings of Balisage: The Markup Conference 2011. Balisage Series on Markup Technologies, vol. 7 (2011). https://doi.org/10.4242/BalisageVol7.Sperberg-McQueen02.

One of the reasons to come to a conference like this is to learn new things. And as Tommie Usdin reminded us in the opening session Usdin, confrontation with other people and listening to things other people have done, including (or even especially including) things we don’t expect in advance to find especially interesting, can open our minds to new possibilities. And opening new possibilities is, in a way, how many of us presumably got here.^[1]

One reason to get interested in a new technology or a new programming language or a new markup language or a new kind of document language is that it opens up possibilities that you didn’t have before. By looking at SGML and thinking about what SGML gave us, those of us who got interested in descriptive markup in the form of SGML learned about ways in which WordPerfect or WordStar or Waterloo Script or troff had been closing down possibilities for us — possibilities we hadn’t missed because we hadn’t thought about them, because the tool shapes the hand that wields it and the intellectual tool shapes the mind that uses it. If your document description language is focused, as so many of them were and are, on putting ink on paper, then you’re going to think that document description and information management is about fonts and layout. And it’s only when you get a language that says, “No, documents are about more than that.” (a language that ironically received much of its original impetus from typesetters, who know perfectly well that fonts can change in different renderings of the same document) — it’s only when you see that that you begin to think about other possibilities.

And that opening up of possibilities can easily give you the sense that you are seeing the dawn of a new day.

That’s why some of us at least got interested in descriptive markup as opposed to WYSIWYG. (As Brian Kernighan is quoted as saying, “The problem with ‘what you see is what you get’ is that what you see is all you get.” And when that’s all you’ve ever gotten, you may not miss the things that it doesn’t give you.) That’s one of the reasons that other people got interested in XML as opposed to straight HTML. That’s one reason people get interested in multiple languages instead of a single language or, generalizing, in a metalanguage as opposed to an object language.

New technologies can open new possibilities. So new specs defining new technologies are always interesting. In this context recall the papers we got from Cornelia Davis about the systematic application of new specs in the XML space (and some old specs in the XML space!) to make new things possible Davis, or Eric Freese’s report on EPUB3 Freese, or Piotr Bański’s application of the TEI ODD system to the ISO Linguistic Markup Framework Banski. All of these are showing us ways of opening up new possibilities.

Sometimes new views on existing specs can open up some surprising perspectives, as we found on Tuesday, when Hans-Jürgen Rennau reported on the work that he and David Lee had done on XDML Rennau. And sometimes we get new perspectives, new possibilities, from the collision of existing specs: think of Kurt Cagle talking about the collsion of XQuery and SparQL Cagle. In the other track about the same time, Julien Seinturier had some very interesting remarks about the different way that domain specialists — in his case, linguists — react to XQuery and SparQL Seinturier that made me think about ways it might make sense to change what I teach when I teach XQuery.

Sometimes the collision with other specs leads us to seek better ways of co-existence. You know, sometimes you’d really like to conquer the world and get the other spec out of the way. (SGML did manage to displace ODA; that was a long hard struggle, but I haven’t heard anybody but SGML people mention ODA for a long, long time.) But in the short term, XML is going to co-exist with JSON for quite a while, so I’m glad to see David Lee looking for a way to get back-and-forth without information loss and with at least reasonably plausible translation results so the product of the transformation doesn’t always sound like the output of a badly trained machine translation program Lee. Even within the XML community, XQuery and XSLT are going to co-exist for a while, so Evan Lenz’s ideas for hybridizing them may give us new perspectives for the future Lenz.

People talk about turning over a new leaf. It took me a long time to understand that idiom. Eventually, I concluded that in its original sense it refers to a school boy who has spoiled one page by spilling too much ink turning over a new page, and now it’s a fresh new opening. There’s nothing wrong with this new leaf; it’s full of possibility. The French poet, Stéphane Mallarmé, talks about this. He talks about the empty page whose blankness defends it.^[2] Why does the blankness defend the page? Because the page is currently full of possibilities, and as soon as I write a word on it, I’ve spoiled an infinite number of them. This thought can lead to paralysis, of course.

Sometimes those of us who are predicting the dawn of a new day will also assume or predict that everyone is going to see the beauty of these possibilites, rejoice in them, and adopt this new technology. And sometimes the rosy possibilities that we foresee will accrue only if everybody does adopt the new technology. Some of you will be thinking, along about now, about all of the rhetoric that we regularly hear — I associate it especially with the web application development community — about the advantages of network effects and the advantages of ubiquity. I think the biologist Richard Dawkins^[3] has spawned (particularly in the IT community for some reason) a whole generation of intellectual social Darwinists who evaluate ideas exclusively in termes of how widely they spread, and not how how coherent or true they might be. This is a sort of propagandists’ view of ideas, whose coarseness and naïveté would shame even the most outrageous of the 19th century thinkers who invented that misapplication of biological theory to human ethics which is social Darwinism.

So it’s nice to have some cases where advantages will accrue and new possibilities will open up regardless of whether anybody else sees them or adopts the new technology or not, where the advantages accrue for individuals and not just huge collectives. It's nice because it frees us from the need to make technological choices based solely on our predictions about what other people are going to think is good technology; it allows us to evaluate the technology on its merits. As technical people, most of us are likely to be better at evaluating the technical merits of technologies than at predicting the crowd psychology of marketplaces. As Michael Kay said several times during this conference, “I really hate to try to make predictions about the future. It’s very hard.” That’s true for all of us.

I had occasion recently to reread the paper published by James Coombs, Allen Renear, and Steve DeRose in the November 1987 Communications of the ACM,^[4] and I was struck that they say:

I think that’s true, and it’s useful to focus on the benefits you can get by adopting a technology even if the browser makers or the large community of web application developers never see it and never adopt it. In that respect I’m particulary grateful to Eric van der Vlist for showing us how we can bring hypertext on the web forward into the 1960s^[5] with multi-ended links that run in browsers today without requiring that we persuade the guys at Netscape or Opera or those other places Vlist01.

On the other hand, as that quotation from Mallarmé illustrates, turning over a new leaf may open so many new possibilities that the experience becomes a little paralyzing. Working with metalanguages can make things so abstract it’s hard to find your way. And working with standards or specifications that leave a lot freedom to their implementors and their uses can leave so many possibilities open that you wonder whether you gained anything at all by adopting the standard or using the specification. When you’re using PDFs, at least there is a Big Daddy over there in San Jose that tells the world what PDFs mean, and it doesn’t matter how gnarly they get inside, because the only people who see the gnarliness inside a PDF file are the people who write PDF display software, and most of them work for Adobe and are very well paid, and the others will either do the same thing the Adobe browser does or they will be punished, and we don’t need to worry about it.

XML, SGML, descriptive markup in general, takes away that comforting dependence on somebody else to decide what’s important and what counts. It puts the responsibility on you, and that can be frightening. Even when we do not find it frightening, it can be an onerous responsibility. As a well-known critic of SGML (Darrell Raymond) once said, “Descriptive markup frees authors from the tyranny of typography only to plunge them headlong into the hellfire of ontology.”^[6]

You see traces of that difficulty in the problem that Norm Walsh talked about: the difficulty of finding an editor that end users will like that preserves the freedom that XML gives you Walsh. It’s a lot easier to write simple interfaces if the user doesn’t have that many possibilities. Sometimes freedom is bewildering and threatening. The report by Ravit David and others, on their experience loading XML ebooks, illustrates those difficulties David. Jeff Beck’s report on the self-delusions you may fall into when you’re working in a closed system Beck is also relevant here. One of the sentences that people will remember from this conference is the observation “If XML is like a conversation, running a closed XML system is like listening to the voices in your head.”

And, of course, when anything at all is possible, the person you’re listening to may be lying. I bet most of you didn’t realize that Lynne Price’s game was part of the technical program. I didn’t either until I realized: it’s another instantiation of this problem.^[7] Infinite possibilities include infinite methods of deceit and threat. And even if your interlocutors are not trying to deceive you, they may just be plain wrong, as Ken Sall mentioned this morning Sall. Did Jeff Beck really play on that record, and if so, was it this Jeff Beck or was it a different Jeff Beck? Maybe I have always thought that Jeff was a great guitar player in his spare time — I only saw one side of him, as a markup geek at the National Library of Medicine, but in his secret life he was a rock star. [Laughter.]

Sometimes, possibly for this reason — it seems related — the way forward seems to be not to open up more possibilities but to start closing possibilities down. That’s why many people thought then and think now that Scribe was a step forward vis-à-vis troff. Why? Because it cut off a whole lot of spaces, particularly spaces of bad typography and bad document structure, and put a very limited palette of possibilities in front of the user. It’s one of the things that the designers of XML tried to accomplish with XML: to close off some of the possibilities of SGML. Let’s not fool ourselves; there is a loss of flexibility in XML vis-à-vis SGML. The design goal was to make that loss of flexibility involve the things you don’t care about and not the things you do care about. So XML doesn’t reduce possibilities for the document owners or the vocabulary designers, only for the software developers. There’s a trade-off: You have to think “Which is more valuable to you? Having more conforming parsers than you can count on the fingers of a single hand (and more non-conforming parsers than you can count on fingers and toes, and possibly some fingers and toes of some friends)? Or, on the other hand, the ability to use backslash rather than ampersand as a general entity reference opener?” On the whole, I’m happy to give up on a backslash as a general entity reference open delimiter in order to have more parsers. So I’m happy with that trade-off. And those of us who prefer to use SGML can still use SGML because it’s there; it’s a spec, and its implementations are not going away, although, as far as I know, most of them have not been updated recently.

That same simplification through reducing choices is probably responsible for the fact that many, many more people use TEI-Lite than full TEI. You can’t use full TEI without making an awful lot of decisions. Quite often they’re decisions that you don’t feel in a position to make upfront because until you’ve had some experience you don’t know whether you want that module or not. Blind interchange similarly requires closing off possibilities and reducing variation. (We’ll come back to that.) To write any text at all on the page — even a text as beautiful as the poem Sea Breeze — Mallarmé Mallarme had to take a stand; he had to put something down on the page. He had to shut out an infinite number of other possible texts in order to get the text he did write, and he had to risk an ink blot or two. Similarly, growing up requires that you stop changing your mind about what you want to be when you grow up and start focusing; at least, that’s what I’ve been told by people who have grown up.

Even at relatively low levels, regularity, predictability, and explicit structure can open up new possibilities. The simple regularity of markup — the ability to distinguish markup from non-markup — allows Daniel Jettka and Maik Stührenberg to produce tools to do visualization of documents Jettka. You know, visualizing the structure of TeX documents or troff documents would be an NP-complete problem. It would require artificial intelligence because you would essentially have to write a troff processor and then you’d have to do artificial intelligence to analyze the shape of the page to decide what the structure of the document was. Having the structure explicitly marked allows Jettka and Stührenberg to draw trees without occupying the mainframe computer center for three weeks in order to document the structure of the first document they try, and then another three weeks to get the second one to compare with it. Consider the paper of Jean-Yves Vion-Dury, in which he exploits the distinction between markup and content in order to encrypt them differently so that you can semi-trust people, semi-trusting your service vendors so they can perform operations without having to understand either the operations or your documents fully Vion-Dury. You couldn’t do that if you didn’t have a reliable guide to the structure that you’re exposing to them (or, in some cases, potentially hiding from them) independent of the content. Or recall the work that Jacques Durand did in XTemp Durand; I think that’s aided by the generality at one level and the utter predictability at another level of the message structure of the messages they have to deal with.

Now, the difficulties of uncertainty and freedom, and the advantages of restriction — I’m tempted to say “voluntary slavery” — apply not just at the psychological level and not just at the application level (even at a very low level). Why are Michael Kay and O’Neil Delpratt able to optimize certain things and not others Delpratt? They are able to optimize those things which they can decide at compile time, and they cannot optimize things which cannot be determined until run time. If they know, at compile time, that certain things are not going to happen at run time, then they can compile into byte code, and the stylesheet can run faster. Freedom leads to uncertainty, and uncertainty leads to doubt, and doubt leads to ... slower processing ... at many, many levels.

Eliminating the possibilities that you don’t want to exercise can help in a lot of ways. To inter-operate with other software, to make XML data more tractable for people who don’t have an XML mindset requires clean APIs — requires APIs like the one Liam Quin sketched, which try to make XML easier to write for people who don’t think in XML Quin. We may wish that they would just start using native XML programming languages like XQuery and XSLT, but historically they have perversely enough exercised their freedom not to do so. And rather than putting them in chains and forcing them, it’s probably a good idea to try to make things easy. Similarly, I’m happy to see the work on XML serialization into C# and Java Objects that Carlos Jaimez-Gonzalez described Jaimez-Gonzalez, or the packaging work that Chris Maloney described this morning Maloney. To make progress on certain tasks, including the development of applications, can just require that you put your head down and you make decisions and you put a stake in the ground and you risk an ink blot or two.

Recall the work of Julien Seinturier on XML engines for multimodal linguistic annotations Seinturier, or similarly, Alexander “Sasha” Schwarzman’s description of the work he and others have done dealing with all the complications of supplemental material for journal articles Schwarzman. Those case studies reflect one of the kinds of work we need to do in order to make XML realize some of the possibilities for our culture that we want it to realize, even though, of course, one of the first things you discover when you do that kind of work is that you’ve uncovered a whole lot of new problems you didn’t know you had before, including the perennial problem “Oh, this is really interesting, but who is actually going to pay for this additional work for the preservation of this additional material?” We now know it’s essential, but we haven’t necessarily found new income.

I have seen the future, and it will require better documentation.

That’s part of the cussedness of human beings. Human beings can do things in a whole lot of different ways. We can understand each other because out of the infinite number of possible human languages, there is only a finite number of human languages actually in use at any given time and an even smaller finite number that are typically used in a particular location. So if we address each other in 21st-century English or 21st-century French, here in Montréal, we’re likely to succeed fairly quickly in finding a language that our interlocutor understands. Fortunately, we can restrict our attention to 21st-century English and 21st-century French — We don’t have to experiment with Chaucerian English or Old High German or Gothic or Uyghur or historical versions of that very large number of attested languages. But if we want to preserve our information for the long-term, the recipients of that information in the long-term won’t have all of the context that we have that reduces the number of possibilities we have to try. So as David Dubin reminded us the other day Dubin, we are going to have to document things a lot better than we might think. It is precisely those things which are so obvious that we don’t think of them as needing documentation, the things that would be almost an insult to say explicitly (because it would make your interlocutor wonder whether you doubt their mental capacity) that may be most important to document. So I’m glad that people like David Dubin or people like Daan Broeder and Andreas Witt and Oliver Schonefeld and their colleagues are working on long-term preservation [Dubin, Broeder] and how to make it work, and trying to figure out how to elicit the documentation that we need and how to store it in ways that people in the future will have a fighting chance at understanding.

Sometimes we may resist nailing things down because there’s the risk of getting it wrong; there is the risk of foreclosing possibilities that were really what we wanted. And I’ll tell you a story I’m embarrassed about: Sometime late in the development of the XML 1.0 spec, Dan Connolly who was the W3C staff contact for the Working Group, said to me, “What is an XML document? Of what set of objects is the set of XML documents a subset?” And I said, rather guardedly, “Why do you want to know?” I had worked enough with Dan that I was worried about a trap. And he said, “It’s just a sort of intellectual hygiene; it’s part of the definition of any set. Modern set theory says if you want to make sure that it’s safe to apply the axioms and theorems of set theory, you have to define sets in certain ways to avoid well-known intellectual problems.” And I said, “You know, I really don’t think that we’re going to run into Russell’s Paradox if we don’t specify whether an XML document is a string of characters or an abstract structure of some kind, so no, I don’t want to go there.”^[8] I have no idea whether anybody else in the Working Group thought about this problem; Dan and I, I think, were talking offline, and I resisted because I did not want to nail down the nature of an XML document in a specific way because I foresaw that other people would use that to sort of close down other possibilities. And the result has, of course, cost later working groups some indeterminate number of months or years^[9] trying to patch problems in the formal underpinnings of their specifications. Some XML specifications, for example, appeal to the notion of identity of XML elements — these two things, they may say, are the same if they are, or are derived from, the same XML element. Sometimes, working group members are surprised to discover that their specification has a hole in its foundation as a result, since the XML spec doesn’t actually define identity criteria for XML documents or XML elements. If identity is not defined for XML elements, you cannot appeal to identity of XML elements to determine the identity or non-identity of other things of interest to your specification.^[10] And it’s my fault.

It would be better to have nailed it down. It would be better to have identified the possibilities I was trying to keep open and define each of them, so that we had terms with which we could talk about them.

Trying to avoid nailing things down may be understandable when you’re trying to preserve possibilities, but trying to avoid clarity is not the right way. So I’m grateful to Allen Renear and his colleagues, even though I disagree with them on the nature of the identifier I42. I’m grateful to them for asking the question “What is the logical form of a metadata record?” Renear It’s the right kind of question; it’s an essential kind of question that we need to ask. I’m grateful to Walter Perry for asking a related question Perry. It’s true that you may risk, when you talk about these things, having someone stand up and say, “I’m lost.”^[11] But we have to ask these questions; it will take us a while to find answers that we can successfully communicate to each other, but if we don’t ask the questions, we’re never going to get there. And I’m grateful to Lars Johnsen and Claus Huitfeldt for the same reason; I don’t understand what those lattices they are talking about mean, but I now know there’s something I have to work on understanding Johnsen.

But now we have a contradiction. (Some of you will have noticed this some time ago, but it took me a while to get around to it.) Now we have a contradiction because on the one hand we want openness and we want freedom and we want flexibility, but we notice that that sometimes leads to paralysis. And on the other hand, we want to avoid closed-down options and foreclosure of possibilities and inflexibility and rigidity, but if we also want blind interchange and interoperability, that seems to be the way to get there. How do we balance these competing interests? Do we have to choose one and let the other one go to the dogs? Can we trade them off somehow? Do we have to choose whether to eat the cake today or save it for tomorrow? Or can we have them both? And what I think of as the big theme of this conference is precisely the question: Can we have them both? In his paper, Eliot Kimber explained the way DITA has striven to make the notion of architectural forms concrete and executable and managed to make DITA comprehensible in ways that I had ever managed to find it before Kimber. The DITA approach, as he described it, seems to provide a way to have a certain kind of freedom within constrained limits and provide precisely the constraints that you need in order to allow at least a certain level of quality in default processing — to have at least some of the advantages of both poles. And if things work right and if you get the right set of primitive types, maybe the advantages you have over here that are preserved and the advantages you have over there that are preserved and not lost are the ones you care about, and the advantages that you’ve lost are the ones you didn’t care about, like changing your delimiters.

Syd Bauman’s talk touched on that very topic of interchange and interoperability Bauman. Wendell Piez discussed ways to provide controlled extension points, not just in the schema and not just outside the schema: having them both seemed to suggest a way that we may be able to manage those difficult trade-offs Piez. I still don’t fully understand this, but the DITA mechanism that Eliot described and the local extensibility mechanisms that Wendell described feel to me similar at some deep level to the definition of forward processing in processor specs.

Another anecdote: The XML Schema Working Group was aware that versioning was a terribly difficult problem, and we were desperately afraid of getting it wrong, so in XSD 1.0 we in fact said nothing. The XSLT Working Group — the group that developed XSLT 1.0 — was also aware that it was important, and they were also afraid of getting it wrong, but they took a risk and defined a forward processing mode for XSLT 1.0 processors. And as Michael (Kay), or anybody who has actually worked with XSLT 1.0 processors in the presence of XSLT 2.0 stylesheets, will tell you, they didn’t get it completely right, and the parts they did get right weren’t always correctly implemented, but ask yourself: “Which set of users is currently in a better situation in the presence of new constructs? The users of XSD 1.0 or the users of XSLT 1.0?” I am in both sets, and I tell you I am a lot happier as an XSLT programmer than I am as a schema writer, because the one way to be absolutely sure of getting it entirely wrong is to say nothing in a misguided attempt to leave all of your options open.

There comes a time for opening things up, and there is a time for closing things down. One part of growing up is realizing that some problems don’t have a permanent solution, so the times for opening things up and the times for closing things down are likely to alternate, and you’ll have to decide what kind of time is this. We’re not going to find any permanent solution to the problem of deciding which kinds of freedom we have to preserve and which kinds of voluntary slavery are worth entering into. Those are questions that require human judgment. One of the things we can do as technology people is to help make tools that will support that human judgment and allow humans to make human and humane judgments and not be consumed by clerical work. To make those tools we are, from time to time, going to have to close down some possibilities, to keep things as simple as they can be (but remember security), to take a stand, to put a stake in the ground, to risk an ink blot, to work not just at a metalanguage level or the meta-metalanguage level or the meta-meta-metalanguage level, but — gasp! — at the object level, to write real documents and real vocabularies and to say relatively concrete things about relatively concrete entities.

Right now it’s time to close down Balisage 2011 so you can all go home and do that work. Soon enough it will be time for the pendulum to swing in the other direction, when what you will want to do is to think about the new things that you learned here that you haven’t thought before, to look at your problems from a new angle, to open up your mind again to new possibilities. I can think of a really good place to open up your mind to new possibilities, to do that kind of thing. So “So long!” and I look forward to seeing you in Montréal for Balisage 2012.