1. A method of teaching a subject matter comprising: administering a first set of one or more question instances to a student, said first set of one or more question instances being based on: (1) source information that relates to the subject matter, and (2) one or more rules that govern derivation of question instances from said source information; evaluating said student's performance on said first set of one or more question instances; and if said student's performance on said first set of one or more question instances does not meet a standard, then repeating said administering and evaluating acts until said student's performance meets said standard, wherein each repetition of said administering and evaluating steps is performed with a new set of question instances that is different from said first set of question instances and different from any new set of question instances that has been already been administered to said student, and wherein each new set of question instances is based on: (1) source information that relates to the subject matter, and (2) one or more rules that govern derivation of question instances from said source information.