SUMMARY

For over ten years there have been several carefully argued critiques of the descriptive markup approach to text representation that have for the most part not been adequately answered. Recently an integrated development of some of these criticisms has been presented at length, and with considerable ingenuity and extension, in a widely read article by Dino Buzzetti, published in New Literary History (2002, 33: 61–88). In our paper we analyze some of Buzzetti’s criticisms, accepting some but resisting others.

BACKGROUND

When the SGML or “descriptive markup” approach to text began to be actively promoted in the mid-1980s, quite a number of criticisms were developed in response to this approach, or, more exactly, to the accompanying theoretical claims, express or implied. In retrospect, it appears today that some of these criticisms have been answered by the proponents of SGML descriptive markup, others have simply faded in apparent significance, and still others, while live issues to some scholars, seem neverless to generate only unproductive repetitive discussions. However there is a particular family of related criticisms that upon careful re-consideration still seem fresh, deep, and, at least given their positive reception, plausible—and yet these criticisms have also been, strangely, largely ignored by the markup community. Some of these arguments were first presented in the late 1980s in a paper titled “Markup Considered Harmful” privately circulated by Darryll Raymond in response to Coombs et al 1987. They were later presented again, in more detail in 1992 in “Markup Reconsidered” (Raymond, Tompa, and Wood 1995); and then were further refined in “From Data Representation to Data Model: Meta-Semantic Issues in the Evolution of SGML” (Raymond, Tompa, Wood 1996). In brief these papers argue that “Markup is not a data model” but rather a “data representation” (Raymond et al 1992), and that while “SGML provides standard representations for documents” a “standard semantics” is required as well (Raymond et al 1996). And then, generalizing from this conclusion, the authors go on to suggest that many of the expectations for SGML-based markup systems, such as TEI, are misplaced. Despite the fact that these were pointed and clearly argued positions, the response from the TEI community, and perhaps more importantly from the theorizing researchers whose ambitious claims were particularly targeted (Coombs et al 1987, DeRose et al 1990, Sperberg-McQueen 1990), appears to have been largely to simply ignore these criticisms. Recently Dino Buzzetti has been re-presenting these arguments, supplementing them with further theoretical extensions, and integrating them with other criticisms of descriptive markup approach, in particular those of Jerome McGann, most recently presented and extended in a new book Radiant Textuality: Literature Since the World Wide Web (New York 2001)—which Buzzetti takes as supporting Raymond’s and his own criticisms. Buzzetti has in fact presented his concerns in several venues over the last 5 years (e.g. Buzzetti 1999a, Buzzetti 1999b), but it is in “Digital Representation and the Text Model” (New Literary History, 2002 33) that he presents these criticisms in a form, and a forum, and a language, in which they can no longer be ignored. Interestingly, this article comes precisely at a moment when some of the theorizing descriptive markup proponents are themselves very actively working in a similar vein. Sperberg-McQueen, who has called for the development of a SGML/XML semantics since at least 1992 (Sperberg-McQueen 1992), is leading a project to develop such a semantics now, and Renear, who is member of this project, has also recently claimed, in language similar to that of Buzzetti and Raymond et al, that an SGML document instance per se provides “only a data structure, not a theory” (Renear 2001).

THE CRITICISM

Raymond et al argue, as described above, that markup is not a “data model”, but only a data representation that is “fully dependent on external information for meaning”. They note several characteristics that they say confirm that markup is not a data model in the sense that that expression is used in database theory. These include inadequate notions of equivalence, lack of redundancy control, and lack of defined algebraic operators. This claim should not of course be taken simply as a narrow assertion that SGML markup does not meet criteria for being a certain sort of thing as defined in some field or other—the larger point, and in the context of the discussion a plausible one, is that SGML markup will be inadequate for the kinds of theoretical tasks it is being assigned in virtue of failing to have these characteristics. Raymond et al (1995) state that this failure can be remedied either by adding a “formal structure on top of markup systems” or by defining a new abstraction from scratch. Raymond et al prefer the latter because they believe that markup systems are not only a representation rather than a data model, but they are in fact a relatively poor technique for representation. Raymond et al 1996 characterizes this addition of a formal structure as adding “semantics” to SGML. Buzzetti accepts Raymond et al’s criticism of SGML markup. But he goes much further, both in the extent of his theorizing and in the specific nature of his criticisms. With respect to the latter Buzzetti argues that descriptive markup theorists are actually confused, and profoundly so: they conflate the “structure of the representation” with the “structure of the object represented”, or, alternatively, they confuse the “expression” with the “content” of that expression. Supplementing Raymond’s criticism from the perspective of database theory with an opposition from Saussure Buzzetti argues that descriptive markup is an expression whose form is a data structure. But the form of the content of that expression is a “data model”. Neither the expression itself nor its form however, is a data model—as mistakenly believed by the promoters of SGML descriptive markup and the defenders of the OHCO model of text. (Buzzetti goes on to make this point with juxtapositions of other theoretical terms: “format” vs. “formalism”, “syntax” vs. “interpretation”). As examples of this confusion Buzzetti singles out in particular the TEI Guidelines, Coombs et al 1987, and DeRose et al 1990, and Renear et al 1996. “In summary,” Buzzetti says, “we may assert that strongly embedded markup systems [are] inadequate in reference to both the exhaustivity and the functionality of the text representation and model.”

OUR RESPONSE

We believe that that there is some truth to both Raymond, Tompa, and Wood’s criticisms, and to Buzzetti’s application of the criticisms. However we believe that both Raymond et al and Buzzetti substantially overstate the case, Raymond somewhat and Buzzetti much more. Such a response may seem too mild to deserve public airing, but it is for two reasons much more important than it sounds: first because of the radical form the criticism takes in Buzzetti, and second because our response might clarify some long confused issues in text encoding. There can be little doubt that many SGML markup enthusiasts have been now and then confused, and, even more frequently, confusing, about the representational nature of SGML document instances. This is mostly because representation itself is conceptually difficult, and subject to a kind of semiotic oscillation between expressing, referring, and exhibiting. And it may also be partly because of carelessness and genuine lapses of clarity and understanding. But Buzzetti makes too much of the fact that we are sometimes awkward about what document instances are, representationally, and exactly how markup does what it does. Notice that for the most part everyone manages the ambiguities quite well, and gets on, successfully more often than not, with various tasks and projects. How could this be the case if there were such a consistent systematic widespread conflation of expression and content? And, in fact, a close examination shows that Buzzetti does not produce evidence for such a systematic conflation, other than the various awkward or unfortunate characterizations mentioned above—and those, while admittedly signs of some failure to fully conceptualize key notions, are far from convincing evidence for systematic conflation. Moreover, there is no evidence that this confusion, such as it is, is connected, as either cause or effect, with a radical unsuitability of SGML markup to express theories about text. (According to Buzzetti “SGML is a data structure representation language” and does not provide a data model; and he echoes the views of Raymond et al that it is, moreover, a bad data structure representation language.) Part of the problem is that Raymond and Buzzetti rely too much in their argument on the specific notion of a “data model” from database theory, and therefore over-react to the failure of SGML to have precisely that sort of data model, or to have a good (i.e. completely or exactly defined) one. Part of the problem is that they demand formalization before admitting that there has been sucessful representation. It cannot be denied that we use SGML document instances to express express facts and theories about texts rather effectively: that is simply an empirical fact. Part of the problem is that in claiming that SGML and XML lack semantics and a defined set of operators, Raymond et al and Buzzetti ignore the fact that both SGML and XML define the semantics of the markup vocabulary in use as an intrinsic part of the application's document type definition. Unlike Raymond et al and Buzzetti, the SGML standard does not assume that the full semantics of an SGML application are captured in full by the SGML formalisms used to declare elements and attributes. Nor does a demand for an exhaustive set of algebraic or other operations seem a promising start for a critique of a markup discipline intended to encourage the reuse of data and the separation of data representation from processing concerns. In this connection Buzzetti’s criticism of the ordered-hierarchy of content objects (OHCO) hypothesis is particularly illuminating, because strikingly unconvincing. Unlike SGML markup, OHCO is obviously not intended as a representation syntax, but rather an abstraction claimed to be, structurally, the general form taken by all texts. As such it actually appears to be roughly the kind of thing that Buzzetti wants for a data model, though without the specific features characteristic of data models in database theory. Buzzetti’s interpretation of OHCO however has it as “not a model of the text, but a possible model of its expression”, just as SGML on Buzzetti’s account, describes not the text, but “the structure of the text’s expression”, consistent with its distinctive role as “a data structure representation language”. But whatever the failures of OCHO as a data model, this is no more than a tortured effort to make things seem worse then they are. The data structures in question have untyped purely logical parent/child relationships, whereas “hierarchy” in OHCO clearly refers to containment—and that is not a purely data structural relationship, despite the obvious formal similarities (asymmetry, transitivity, etc.) that makes tree data structures convenient for representing hierachical containment. It is true that additional formalization of the semantics of SGML markup is a good thing. Formalization will assist in precision, clarity, and computation. It is for that reason that Sperberg-McQueen and others are working to explicate the semantics of XML markup. But while we may regret that such work has not made more progress, or that not everyone understands the need for improved formalization of semantics and “data models”, or that some of our colleagues are sometimes confused about subtle matters of representation, or that we ourselves are now and then confused, or even often confused, we should not conclude that things are worse than they are. Scholars working in SGML descriptive markup are working with languages that do have semantics, and do have “data models”, even if inadequately formalized, or not quite the sort of thing database researchers prefer. And these scholars are at least as often as not quite clear on the difference between expression and content.

CONCLUSION

The criticisms of inadequate formalization that began with Raymond et al and that have recently been so intriguingly developed and extended by Buzzetti are important ones that have been mysteriously neglected by the markup community. And the more ambitious criticisms made by Buzzetti of our failure to fully theorize, or at least attempt to clarify, the complexities of representation are perhaps even deeper and more important, and also unfortunately neglected. But the claim that in these failures we see the signs of either a systematic category mistake endemic in the text encoding community, or evidence of a disastrous inadequacy in current techniques, simply has not yet been proven. On the contrary, as we have suggested here, that claim itself seems to be based upon the mistaken notion, ironically reminiscent of the third man argument, that one more formal system will finally bridge the gap between thought and object. There may or may not be a gap, but if there is it will not be closed simply by another formal system, however useful that system may be.

REFERENCES

Dino Buzzetti. “Text Representation and Textual Models.” ACH-ALLC'99 Conference Proceedings. Charlottesville: , 1999.

Dino Buzzetti. “Digital Representation and the Text Model.” New Literary History. 2002. 33: .

James H. Coombs Allen H. Renear Steven J. DeRose. “Markup Systems and the Future of Scholarly Text Processing.” Communications of the ACM. 1987. 30: .

Steven J. DeRose David G. Durand Elli Mylonas Allen H. Renear. “What Is Text, Really?.” Journal of Computing in Higher Education. 1990. 1: .

Jerome McGann. Radiant Textuality: Literature Since the World Wide Web. New York: , 2001.

Darrell R. Raymond Frank W. Tompa Derrick Wood. “Markup Reconsidered.” First International Workshop on Principles of Document Processing, Washington, D.C., October, 1992. : , 1992.

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Allen Renear Elli Mylonas David G. Durand. “Refining Our Notion of What Text Really Is: The Problem of Overlapping Hierarchies.” Research in Humanites Computing. Oxford: , 1996.

Allen Renear. “Raising the Bar, Text Encoding from a Logical Point of View.” CLiP 2001. : , 2001.

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C. M. Sperberg-McQueen Claus Huitfeldt Allen Renear. “Meaning and Interpretation in Markup.” Markup Languages: Theory and Practice. : MIT Press, 2000.

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