An Information Object that models any entity (Actor) that interacts with any Digital Library ‘system’. An Actor Profile may belong to a distinct Actor or it may model more than one Actor, i.e., a Group or a Community. (Athanasopoulos, et al., 2010)

the process of identifying the similarities between different elements of two diverse schemas. It is often used in conjunction with schema mapping.

A document established by consensus and approved by a recognized body that provides for common and repeated use, rules, guidelines or characteristics for activities or their results, aimed at the achievement of the optimum degree of order in a given context. (ISO/IEC Guide 2:1996 Standardization and related activities – General vocabulary)

A subject--‐based classification that arranges the terms in the controlled vocabulary into a hierarchy.

A taxonomy equipped with a richer vocabulary for describing the terms than taxonomies do. It is equipped with other constructs for better describing the world and allowing to arrange subjects in other ways than hierarchies. These constructs include tagging taxonomy terms with properties like “broader term”, “related term”, “scope note”, and “use”.

see Actor Profile

A component that translates one interface for a component into a compatible interface. It is also known as Adapter or Connector.

A component that translates one interface for a component into a compatible interface. It is also known as Wrapper or Connector.

A component which is responsible for coordinating communication, such as forwarding requests, as well as for transmitting results and exceptions. It is responsible for coordinating communication in object--‐oriented distributed software systems with decoupled components that interact by remote service invocations. Introducing a broker component allows to achieve better decoupling of clients and servers. (Buschmann, Meunier, Rohnert, Sommerlad, & Stal, 1996)

A component that translates one interface for a component into a compatible interface. It is also known as Adapter or Wrapper.

A closed list of named subjects, which can be used for classification. In Library science this is also known as indexing language. A controlled vocabulary consists of terms, i.e., particular names for particular concepts.

(i) facts and statistics used for reference or analysis. (ii) the quantities, characters, or symbols on which operations are performed by a computer. (Oxford Dictionary)

an approach aiming at combining data residing in different data sources and providing its users with a unified view of these data (the mediated schema or global schema).

the process of transforming the elements of a schema in terms of elements of another schema. It is often used in conjunction with schema matching.

An identifiable entity in the Digital Library universe. (Athanasopoulos, et al., 2010)

an agreement between a service provider and a customer that defines the set of Quality of Service guarantees and the obligations of the parties;

the capability of a (Web) service to meet a level of service as per factors such as availability and accessibility;

a design pattern making the clients of a component communicate with a representative rather than to the component itself. (Buschmann, Meunier, Rohnert, Sommerlad, & Stal, 1996)

see Quality of Service;

a set of guidelines or rules governing governing interactions among parties. In computer science, it is a set of rules governing the exchange or transmission of data between devices.

an explicit formal specification of how to represent the objects, concepts, and other entities that exist in some area of interest and the relationships that hold among them” (DOI Handbook Glossary, http://www.doi.org/handbook_2000/glossary.html);

a Data Integration approach based on the description/characterisation of the data source as a view expression over the mediated schema.

a provider of intermediary service linking data sources and application programs (Wiederhold & Genesereth, 1997). An external component hosting the interoperability machinery to mediate between components. Mediation approaches to interoperability are particularly strong in supporting the criteria of autonomy, ease of use and scalability (Paepcke, Chang, Winograd, & Garcia--‐Molina, 1998).

a Data Integration approach based on the description/characterisation of the mediated schema in terms of a view over the data sources.

a data manipulation task oriented to make consistent a set of data.

the point of interconnection between two entities.

the ability of two or more systems or components to exchange information and to use the information that has been exchanged. (Geraci, 1991)

An organisation, which might be virtual, that comprehensively collects, manages and preserves for the long term rich Information Objects, and offers to its Actors specialised Functions on those Information Objects, of measurable quality, expressed by Quality Parameters, and according to codified Policies. (Athanasopoulos, et al., 2010)

an abstract model capturing the distinguishing features of a data set and describing how data are represented.

A software system based on a given (possibly distributed) Architecture and providing all the Functions required by a particular Digital Library. Actors interact with a Digital Library through the corresponding Digital Library System. (Athanasopoulos, et al., 2010)

A generic software system that provides the appropriate software infrastructure both (i) to produce and administer a Digital Library System incorporating the suite of Functions considered fundamental for Digital Libraries, and (ii) to integrate additional Software Components offering more refined, specialised or advanced functionality. (Athanasopoulos, et al., 2010)