1. How Five Industries Will Benefit From the Grove Paradigm Steven R. Newcomb srn@techno.com TechnoTeacher, Inc. HyTime Track, XML Europe 1999, Granada, Spain, April 29

2. 2 How this talk is not the same as the paper... The paper in the Proceedings is organized by industries. This talk is organized around the features of the grove paradigm that are useful to those industries. Much has happened since the paper was written. There are more than five industries involved in grove- based projects.

3. 3 First, what’s a grove? Some definitions: A set of interconnected nodes conforming to ISO/IEC 10744:1997 Annex A.4. Ready-to-run objects. The application-internal information that is being created, edited, or used by an application. The form of information that is the result of parsing an interchange document (written in XML, for example). Information that is present in an interchange document, but which, for application programming, is structured differently in the grove. The abstract API to the information set.

4. 4 But that’s the DOM, right? No. The DOM is an API. A grove is a set of nodes -- no methods. : But it’s true that an API to a grove of an XML document could serve the same purposes as the DOM. : And the DOM is an example of an interface to an XML grove. Groves are more powerful, general and sophisticated.

5. 5 Use by reference Groves allow any component(s) of any resource(s) expressed in any notation(s) (XML or non-XML) to be transcluded into any components of any resources expressed in any notations (XML or non- XML),...without changing any of the resources involved. Groves allow there to be a single authoritative copy of each datum, regardless of its notation. Groves allow each datum to be expressed in the most cost-effective notation.

6. 6 Linking Groves allow any component(s) of any resource(s) expressed in any notation(s) (XML or non-XML) to be hyperlinked to any components of any resources expressed in any notations (XML or non- XML),...without changing any of the resources involved.

7. 7 Links are valuable assets Groves allow the links to be exported as standards-conforming, non-proprietary XML documents. Specifically, groves allow addresses to be expressed in conformance with standards. Standards-conforming software from any vendor can resolve the addresses.

8. 8 Management of links and uses-by-reference Groves provide knowledge of all anchors of all links, and of the links of all anchors, regardless of the notations of the anchors. Groves provide knowledge of all the sources of the transclusions in each document, and of all view documents into which any given transcluded material is transcluded, regardless of the notations of such sources.

9. 9 Management of links and uses-by-reference Groves allow links and uses-by-reference to be classified via inheritable common architectures, as well as by the application. Groves greatly facilitate applications that provide traversal and transclusion services. Groves allow the side effects of changing an information asset to be predicted.

10. 10 Technology independence Groves can support software that creates and maintains links, bookmarks, annotations, auditing records, etc. that cannot be lost merely because of subsequent changes in computer technology, or changes in system vendors. All such referencing information can be stored in freestanding XML documents that contain addresses expressed in a way that is correctly resolvable by any grove-aware application.

11. 11 Bookmarks Groves allow the notes of caseworker professionals, expressed in XML, about particular casefiles can incorporate bookmarks to components of materials in any notation, without changing the materials. Such notes can be used to provide continuity of corporate behavior toward (and understandings with) customers, without changing the casefiles themselves.

12. 12 Shop notes Groves allow shop notes to be maintained by shop floor technicians in documents that are separate from the manuals. The notes can be made to appear as if they were actually part of the documents (or not). Subsequent versions of the manuals can have the same shop notes, without having to update all of them.

13. 13 Scalability Lightweight in-memory grove-based applications are practical in PDAs. Lightweight ISAMs can support PC-oriented grove applications. Heavyweight object databases can support large repositories of information resources. Mammoth grove-based systems are supportable with multiple databases. The links expressed by resources within them can address anything in any database, thus tying everything together into what is, in effect, a single gigantic database.

14. 14 Topic maps "The GPS of the Web" -- Charles F. Goldfarb. Topic maps are supportable without groves, but not in their full generality and not at their full power. Topic maps are insupportable without independent linking. (It's very hard to support independent linking without groves, and very easy with groves.)

15. 15 Workflow Groves allow everything about workflow, regardless of the notations of the produced work, to be driven and controlled by XML documents containing annotating hyperlinks. The components of information resources that need review, editing, rework, approval, or re- publication, or for which proposed changes exist, can be appropriately annotated, without changing them, : regardless of the notations in which the resources are expressed, or the manner in which they are stored.

16. 16 Programmer productivity The grove paradigm elegantly fits all applications involving the addressing of arbitrary information components. : Every node is as addressable as every other node. : A node can be anything: ! from a whole document to a single character, ! from a movie to a pixel, ! from a complete engineering drawing to a single polygon, line, or point.

17. 17 Programmer productivity Even incoming ephemeral information, such as the information arriving from the diagnostic connection harness of a piece of equipment that is being repaired, can be a grove that is as useful as any other grove. Databases can be made to appear to be groves. Metadata can be grove-ified. (Example: WebDAV.)

18. 18 Notation processors A Notation Processor can be the application's mature and highly capable partner for chores common to applications that use and/or manipulate data that conforms to : a notation, : a class of information objects, or : a database schema.

19. 19 Auditability of transactions Groves allow transactions involving : creating, changing, and deleting content : creating, changing, and deleting links to content : re-using (and ceasing to re-use) content...to be as auditable as desired.

20. 20 Locally controlled DTDs Groves allow applications to support inheritance of information architectures (meta-DTDs). Meta-DTD-specific property sets mean re- usable software modules, so : Groves reduce the cost of software : Groves increase the uniformity of interpretation of data by applications. ! This is vital in e-commerce involving technical product descriptions.

21. 21 A demonstration of a grove management technology.

22. 22 DOM vs. Grove The main difference is that the DOM is not schema- driven. It has a single (implicit and as-yet- undocumented) schema -- a schema for the XML notation. : The DOM can only be used for documents expressed in XML, whereas any information, in any notation, can be represented as a grove. : Even in XML-land, the DOM does not provide access to the information sets conveyed by specific XML document types, whereas a grove can be a set of nodes that reflect the information set, and that may bear little resemblance to the interchange form of the same information.

23. 23 What about the XML Information Set? The W3C's XML Information Set project is a great thing, and it is urgently needed in order to allow the addresses of XML document components to be interchangeable. If the XML Information Set were expressed as a “Property Set”, then it would be a description of a grove -- an XML grove. In any case, it will be very similar to a property set for XML. The XML Information Set is expected to be a description of the features of XML, but not described in a fashion that could be used for other notations.

24. 24 The Mainstream is More than XML There will always be plenty of notations other than XML. Their components must be addressable so that they can participate in the mainstream of information processing. Groves allow that to happen.

25. 25 XML DOM solutions are for XML XML DOM solutions don’t allow information to be expressed in any form but XML. All information has to be converted into XML. : Conversion is expensive. If information changes, it's a recurring expense. : Conversion takes time, so the XML version is not always up to date. : What if you have created links and other references to the XML form, and the original changes? : What if you have changed the XML form, and need the changes to appear in the original form? Reconversion may be even more expensive!

26. 26 Groves: No conversions necessary. Grove-based solutions allow the information to stay in its original form, without requiring it to be converted into XML. : This is essential, for example, where products are being produced, delivered, maintained, supported, redesigned, redocumented, and delivered simultaneously. : All five industries, and many others, share this requirement.

27. 27 How does the Grove Paradigm work? (1) For a given notation, the interesting aspects are named in a schema called a “property set”. : For example, in a property set for photographs, we might say, “People's noses must be addressable. Let’s make sure all the noses become nodes in the grove that is made from photographs. We'll call such nodes 'Nose Nodes'.” : So, it’s like writing a DTD for information that isn't in XML: you decide what’s interesting about some set of information, and you give each such thing a property name, which is like creating an element type name.

28. 28 How does the Grove Paradigm work? (2) When you create a grove, everything that was regarded as interesting: : exists in the grove (and nothing that wasn’t interesting is there), and : in effect, every component says what it is. It’s like tagging, but without the tags.

29. 29 If I Have XML, the DOM, etc., Why Groves? You need to be able to talk about things other than XML. “Talking about things” means being able to point at them, so you can say what you’re talking about. If you never need to talk about anything that isn’t already in XML form, THEN YOU DON’T NEED GROVES! The reverse is also true.