A messaging system can initiate a communication with one or more users through via cell phone text messages, for example using the short message service protocol. These systems often need a way to correlate user responses with system requests or queries. This problem can present challenges because the email mailbox metaphor used by cell phone user interfaces generally allows users to reply to any previously sent messages, but no message context is automatically supplied. A system that may send multiple messages to a user needs a mechanism by which the system can correlate a user-sent response to one of potentially many system-sent requests or queries. Context correlation to resolve ambiguities can be based on one or more of a dialog-based solution, a token-based solution and a keyword-based solution.