The document discusses the cross-search aggregation service called Perx, highlighting its role in enabling engineers to efficiently find information from various repositories. It describes the architectural setup of Perx, including the service registry and the community interactions that support data providers and service managers. Additionally, it raises questions about information exchange and the ecological dynamics of the Perx system's operation.

1. Cross-Search Aggregation Service Management: a sketch of a habitat in the repository ecology Author: Phil Barker <philb@icbl.hw.ac.uk>, Heriot-Watt University Last modified: June 2007. See also: http://www.icbl.hw.ac.uk/publicationFiles/2007/CrossSearchEcology/index.html This work is licenced under the Creative Commons Attribution 2.5 UK: Scotland License. To view a copy of this licence, visit http://creativecommons.org/licenses/by/2.5/scotland/ or send a letter to Creative Commons, 171 Second Street, Suite 300, San Francisco, California 94105, USA.

2. The PerX Use Case An Engineer is engaged in some work...

3. The PerX Use Case An Engineer is engaged in some work, when suddenly they require further information to complete their task ?

4. The PerX Use Case So the Engineer goes to their computer and performs a search on the PERX website. ! See http://www.icbl.hw.ac.uk/perx/

5. The PerX Use Case The PERX systems cross searches a series of repositories of interest and as a result the engineer finds the information needed to complete the task effectively. The world is made a better place.

6. IE Architecture view See http://www.ukoln.ac.uk/distributed-systems/jisc-ie/arch/ The website used by the Engineer is a presentation layer connection to PerX. The PerX service is an aggregator in the fusion layer of the IE architecture, it cross searches information about resources which is held by several services in the provision layer. PerX knows the nature of these content provider services and how to search them because of data provided by a service registry which is part of the shared infrastructure. Other shared services (not shown) may be involved in delivering the resource.

7. Ecology View : PerX Landscape analysis See http://www.icbl.hw.ac.uk/perx/sharedservices_IESR.htm The PerX service manager needs to identify suitable data providers and set up connections to them using the Perx Admin INterface (PAIN). The Service Registry does not (yet) contain reliable information to help him. No machine to machine connection is implemented.

8. Ecology View : PerX Landscape analysis However, the PerX service manager has access to a community of people active providing information resources for engineers (for example the service managers of data providers). This community is in contact with the Engineering community in order to ascertain the needs of Engineers and so can provide information on providers of data about information resources relevant to engineers. See http://www.icbl.hw.ac.uk/perx/sharedservices_IESR.htm

9. Ecology view: PerX Setup & Maintenance In order to set up and maintain a cross search of a data provider the PerX service manager uses information from the data providers website, other resources provided by the information community, and ultimately, a great deal of direct contact with the data provider service manager. See http://www.icbl.hw.ac.uk/perx/setupmaintenance.htm and http://www.icbl.hw.ac.uk/perx/casestudyoxford.htm

10. PerX habitat : the full(?) picture

11. Points to investigate further Are there any other players that should be identified? What is the nature of the information that is passed to the PerX service manager? Through what channels is this information passed? What are the “abiotic” factors and what effect do they have on the entities and their interactions? The service registry and the information communities perform similar functions (both provide information required to set up cross searches): how do they interact? ...