Abstract: A first query and a second query, both of which were submitted by a first user to identify information that satisfies a single information need of the first user, are received. The first query and the second query are stored in association with one another and based on a chronological order in which the first query and the second query were submitted by the first user to generate a first query reformulation path. A query is received from a user and more than one query reformulation path is accessed. The received query is compared with queries included in the accessed query reformulation paths to identify a relationship between the received query and a query included in a relevant query reformulation path. One or more prevalent end points is determined based on the relevant query reformulation path and at least one of the prevalent end points is presented to the user.

Abstract: A system and method for data storage and removal includes providing databases and providing encryption keys. Each database is associated with a database time period and each encryption key is associated with an encryption time period. Data items are received and each data item is encrypted using the encryption key associated with the encryption time period that corresponds to a time associated with the data item. Each encrypted data item is stored in the database associated with the database time period that corresponds to the time associated with the data item. Each encryption key is deactivated at a predetermined time after the associated encryption time period ends. Each database is made irretrievable upon a determination that all of the encryption keys associated with the data items stored in that database have been deactivated.