Eric Armstrong


Date: Fri, 12 May 2000 15:54:36 -0700

From:   Eric Armstrong

To:     unrev2

Subject:   Current Proposals
Meeting at SRI on May 11, 2000 Re: DKR

At yesterday's meeting, Jack and Howard, based on a meeting with Doug, proposed that source documents (HTML, source code, etc.) would be translated into an XML-based OHS format and stored in the OHS repository in that format. [Note: That is the XML model I have been assuming.] The documents are then transcoded for display.

Lee Iverson then proposed a different idea, where the OHS-XML document does not carry the information directly, but instead consists of pointers and links into the original document. The original document remains intact. [That sentiment echoes design concepts proposed in a message by Sandy Klausner.] He further proposed that the source document could be transcoded to produce that "OHS wrapper", rather than translated.

[Definitions: Format A is "transcoded" to Format B if you use Format B for a while and then discard it, so you re-access Format A and transcode it again the next time you need it.

Format B is "translated" to Format B if discard Format A after you are done and use Format B from then on.]

My proposal has been that the operations on the OHS only take place on documents in OHS-XML format. You make the DTD open, provide email/browser tools, and encourage others to do so as well. The benefit of that proposal is that it simplifies the project. The potential cost is that because people are not working in their native document format, it reduces participation, possibly to below the desired "critical mass" levels necessary to ensure success.

Jack and Howard's proposal is the closest to that, with one important difference: The original source documents are viewed as *part* of the OHS, rather than lying outside it. In my view, they are translated one time to get into the system, and after that ignored. In their proposal (I think) those documents are viewed as part of the system.

The major issue I see with that approach (and have not yet been argued out of) is that of managing change. What happens when the underlying source document changes? How is the OHS-XML version informed and modified in such a way that any links made to that document remain pointed to their intended targets?

I see that as the central issue in Lee's proposal, as well. How do you reflect document changes in the OHS-XML index of the document? And for both alternatives, do you allow modifications from within the OHS and, if so, what becomes of the original document.

Lee seems to feel that these issues are resolvable. He suggested that the source documents would be under a source control system like CVS or SCCS, and that would make a difference. If so, the implications are:

Lee also felt that the Source Development System (SDS) at...

...provided answers to some of these issues.

Unfortunately, just as we were about to examine the issues in depth, discussion had to stop.

[Lee, can you elaborate on how change-management issues can be resolved?]


Eric Armstrong