Patent ID: 8903855

Claim:
A database comprising a memory and a storage system arranged to hold a plurality of sets of records, a first set of records corresponding to content items for deliver to potential respondents, and a second set of records corresponding to potential responses to the content items from actual respondents, wherein the database comprises an interface for use in specifying: a first set of links between individual content items of the first set and responses of the second set, each said content item being capable of having a link to more than one different response of the second set and the database being operable to further store first link data indicative of a plurality of different links between a given individual content item and a corresponding plurality of responses of the second set; and a second set of links between individual content items of the first set, each said content item being capable of having a link to one or more other content item, the database being operable to further store second link data indicative of a plurality of different links between the one content item and a corresponding plurality of said other content items.