## 7 Discussion
It is in this context that it will be necessary to ask questions such as what is the best search path for which situation and setting. * Should search be pursued via hierarchical, peer-to-peer, or alternative network paths? * Which search path is best when attempting to locate a resource known to exist somewhere? * Which search path is best when attempting to establish the existence of a resource not known to exist _a priori_? * Which search path is best for a commoditized resource for which any instance will satisfice? * Which search path is best for a uniquely individual resource for which only the unique instance will suffice? These questions relate to investigating and elucidating the search problem of identifying and locating an unknown network node in contrast to finding the optimal network path between a known source node and a known target node. In other words, establishing a communications channel as a network path for the movement of data between a known origin and known destination remains fundamentally a different problem than the search and discovery problem for an unknown, possibly nonexistent, node in a network that spans the globe. In response to these questions for future study, consider the Hierarchically Distributed Mobile Meta-data (HDMM) architectural style (see Section 4 and the \"Beacons of Gondor\" metaphor in Figure 1) that characterizes both the IRIS-DNS System and PORTAL-DOORS System as distributed registry-directory who-what-where metadata management systems. Consider also the success of the IRIS-DNS System for the original web. Assume that comparable success could be attained by the PORTAL-DOORS System for the semantic web if it is successfully developed and deployed into a distributed network cyberinfrastructure as extensively as the IRIS-DNS System. If so, then the following prediction, called the HDMM Conjecture, can be stated as a formal hypothesis to be tested. **HDMM Conjecture:**_Semantic HDMM networks should scale more efficiently than semantic peer-to-peer networks and thus should be more useful for searching by various query criteria for an unknown resource entity at an unknown resource location,_ i.e., _when existence of the resource is not known a priori._  
Section 3 provides additional discussion of the intuitive analysis, assumptions and claims that led to this conjecture. Future work with rigorous experiments and simulations comparable to those for large-scale networks [57, 58, 59, 60, 61], peer-to-peer networks [62, 63, 64] and super-peer networks [24, 26] will either prove or disprove this conjecture. In the conduct of these experiments and simulations, careful attention must be paid not only to the definitions for each model (hierarchical versus super-peer versus decentralized peer-to-peer), but also to the different applications and corresponding sets of parameters, requirements, and constraints that pertain to each application. For example, Mastroianni [26] provides evidence in support of the super-peer model when applied to orchestrating the commodity of computing services in a multi-organizational grid. However, without reference to careful _ad hoc_ usage and definition of terms and models in the context of the application and any experiments comparing different models for that application, generic usage of the term _super-peer_ may blur the distinction between _hierarchical_ and _peer-to-peer_ especially when a term such as _hierarchical_ can itself be used in so many different ways as discussed in Sections 2.1 and 4. Does this model question concern the process of registration, identification, publication, location or description? In the context of the HDMM architectural style for the IRIS-DNS and PORTAL-DOORSSystems which both permit mirrors of the roots and pervasive redistributed caching of all mobile metadata records, should the HDMM systems be construed as hierarchical, super-peer or peer-to-peer?