13. The computer program product of claim 11 , wherein the one or more key attributes are textual terms.
15. The computer program product of claim 13 , wherein determining, for the relational context corresponding to the selected group, based on personal information data corresponding to the selected persons in the selected group, one or more key attributes in the personal information data, comprises: identifying one or more key terms based on a terms listing data structure specific to the relational context; determining a relative rarity measure for each key term in the one or more key terms based on a relative number of occurrences of the key term within the corpus of personal information data; and generating the relative rarity matrix data structure based on the relative rarity measures of the one or more key terms.