Given-New vs. Analogy--
Today's blog is for die-hard writers who get a buzz from talking about rhetoric. No tools or technology today; I'm going through enough of that on the day job :-)

I was structuring a formal analogy the other day, you know--A:B::C:D (read A is to B the way that C is to D), and wondered what the preferred sequence should be. Should the new relationship be in the AB slot with CD being the relationship the reader is already familiar with, or should AB be the familiar relationship and CD be the one that is new to the reader?

I've always been a big fan of using a Given-New rhetoric when trying to explain complicated material. In that scheme you make the topic (subject) of the sentence some concept the reader is already familiar with, and you introduce the new concept in the predicate. Then the next sentence can take the predicate from the previous sentence and make it the subject, since it has now become a "given." The technique allows you to build up a knowledge base, so to speak, within the reader in small, manageable steps.

For example, let's say you had to explain DITA to a reader base for whom it would be a new concept. Watch how in the following text, the subjects of the sentences are concepts that are already familiar to the reader. Pay particular attention to the dance that ensues from a concept going from the predicate position in one sentence (where it was the "new" concept) to being the subject in the next sentence (because it is now a "given" concept). The following explanation assumes that the concept of structured writing is a familiar one to the reader.

A form of structured writing that has gained much popularity in recent years is DITA. DITA stands for Darwin Information Type Archictecture and is an XML-based approach to authoring. XML is the mark-up language that enables authors to share content across different platforms and among different documents.

You get the idea. This is a blog and that was a quick example, so don't edit me too critically on it. Like any horse, Given-New can be ridden to death and its overuse can leave your discourse sounding "sing-songish" and feeling mechanical. None-the-less, I have found that it is often a good technique for first drafts of paragraphs where I feel I have to move the readers across a rather large gap between what they already know and what they need to know.

But that logic didn't "feel" right to me when trying to put an analogy together; the order of New-Given seemed better within that device. For example, let's say I am trying to explain DITA topics to someone who is already familiar with Information Mapping. Which of the following analogies works better?

• Topics in DITA are similar to maps in Information Mapping.
• Maps in Information Mapping are similar to topics in DITA.

I think the first works better even though it is leading with the new concept and relating it to a given. Maybe because in context, it would appear in a discussion about topics, and, at least in that context, it would be the given topic.

But beyond that, I think there is something to be gained in an analogy by posing the strange relationship first and then grounding it in the familiar. It seems to be consistent with a principle I have noticed in instructional design: Students have no way to process a solution until they experience the problem. In other words, it's best to raise the question before providing the answer as an isolated fact.