Where semantics lies

Should the syntax of XML have been scrapped in favor of s-expr essions? This debate, which raged for years, and which occasionally reapp ears, has all the ring of a religious war (Windows vs. Mac, Emacs vs. Vi, big-endian vs. little endian, and so forth). The risks we take in even broaching the subject are manifold. A talk based on a question like this is destined to be both technical and phil osophical, which is to say, bad. And try as I might, I will undoubtedly seem guilty of favoring one side or another, whatever protestations I might make to the contr ary. It is in the nature of religious warfare to be on one side or another, and to be wro ng either way. But my purpose here really isn’t to settle this question, or e ven to re-introduce the debate. What I want to do is use this mostly wrong-headed b ack-and-forth to shake out something that I think is actually highly releva nt to the topic of data modeling—in the humanities, or anywhere else. That highly r elevant point can be stated pithily by asking “where the semantics lies” in our co mputational systems. In fact, what I’d like to say, is that this issue subtly affect s the way we think about data modeling, even when we try to think about data mode ling in complete isolation from any concerns about the use of data models, or e ven, for that matter, computational tractability. But before I launch on this hopefully meaningful quest for th eological insight, perhaps I should explain the terms of the debate that give ris e to these meditations. What, to start with, is an s-expression? An s-expression is a notation for representing tree structu es, and it looks like this: