Subject: Re: [soa-rm] Diagram
|And what may help clarify things (or may just bring back the old muddy waters) is a recent write-up where I distinguished between what I called direct and indirect discovery. |
An entity may be directly discoverable or indirectly discoverable. For the discussion I was doing at the time, indirect discovery would be accomplished through search of a registry where the description of the entity has been catalogued and discovery is accomplished by matching the user's criteria to the catalogued entity description. However, it should be noted that there are other discovery mechanisms such as direct discovery by browsing for an entity at known locations. For example, an NCES discovery service could be accessible from a link on the home page of a DISA portal. You go to the portal because you expect to find a link prominently displayed; this is as much based on expectations for the functions of the portal as it does anything about the discovery service. As another recent example, many corporations have been responding to natural disasters by having prominent links on their home pages pointing to relief organizations or ways to make immediate contributions that would be passed to such organizations. This has created an implicit expectation that a certain set of home pages will enable direct discovery of pertinent links, and no other searching is required. One can also imagine a business model where certain portals specialize in advertising specific types of services. Note that discovery could make use of both direct and indirect methods, such as browsing a taxonomy to identify a class of entity and then searching a registry for entities catalogued as belonging to that class.
In both of these cases, the entity must have sufficient visibility (no matter what the visibility mechanism) so that it can be discovered when someone looks for it.
Hope this moves things forward.
On Dec 7, 2005, at 9:33 PM, Francis McCabe wrote: