OpenAIRE2020 - Wiki

h1. Type: Instance

|_Property_|_Type_|_Multiplicity_|_Description_|

| License | [[type_qualifier|Qualifier]] | 0..1 | The license value associated to the instance |

| Embargo end-date | Date | 0..1 | empty if the licenseClass does not imply an embargo |

| Instance Type | [[type_qualifier|Qualifier]]  | 0..1 | Instance typology as described by a defined vocabulary |

| WebResource | String  | 1..N | http url of the resource |

|_Relationship_|_Target	Type_|_Multiplicity_|_Description_|

|CollectedFrom [1]| Datasource |1..N| A Datasource from which this instance has been collected (e.g. an aggregator of institutional repositories) |

|HostedBy [1]| Datasource |1..N| A Datasource that hosts the instance (e.g. an institutional repository) |

[1] The difference betweem collectedFrom and hostedBy relationships is introduced to model the concept of Aggregator data sources. Aggregator data sources are themselves aggregating information packages from a set of data sources; they differ from the data sources they aggregate, but play an equally important role in delivering the entities to OpenAIRE, and should therefore be given visibility. Accordingly, in order to guarantee visibility and ROI (Return Of Investment) to all data sources involved in this chain, when OpenAIRE collects information packages from Aggregators such packages are characterised by the data source from which they were “collected”, i.e. the aggregator itself, and the data sources where they were originally "hosted". Note that in the case of other typologies of data sources (e.g. repositories) collectedFrom and hostedBy refer to the same data source.