1. A personal search agent system, comprising: a user agent configured to: transform a query from a user into a search task assignment, send the search task assignment to one or more server-based search manager agents, and receive one or more responses to the search task assignment; a user miner agent configured to: observe the user's interaction with the user agent or agents, and learn the behavior and preferences of the user; and a data mining agent configured to: analyze the responses to the user's queries, and build a conceptual network of the knowledge contained in the response, wherein the data mining agent further learns associations of natural language artifacts in unstructured data sources, wherein said artifacts include at least one of words, phrases, subjects, predicates, modifiers, and other syntactic forms, wherein learned associations resulting from said learning associations of natural language artifacts are formed using grouping of one natural language artifact with another at least one natural language artifact, based on a criteria of shared features of one or more sets from said grouping constituting measurements from said data sources, wherein said criteria of shared features are dynamically determined without the use of a priori classifications and using conditional probability constraints between sets of learned associations, and wherein said grouping creates a network of conditional probabilities between all encountered natural language artifacts or a subset thereof, determined by consideration of conditional interaction probabilities based on a history of measurements from said data sources.