1. A computer implemented method of extracting information from one or more documents, comprising: receiving a training and execution plan that specifies invocation of a trainer operator for initiating training of a trainee operator based on a set of training documents so as to generate a trained operator that is to then be invoked so as to extract information from one or more unknown documents, wherein the trainee operator is configured to extract information from one or more unknown documents and each training document is associated with classified information; after receipt of the training and execution plan, automatically executing the trainer operator to train the trainee operator based on the specified training documents so as to generate a trained operator for extracting information from documents; after receipt of the training and execution plan, automatically retaining the trained operator for later use in extracting information from one or more unknown documents; and after receipt of the training and execution plan, automatically executing the trained operator on one or more unknown documents so as to extract information from such one or more unknown documents.