1. In a computer-based system, a topic-interpreting method for delivering instructional material from a database divided into segments to be accessed for display of said material on a screen of a computer-access terminal, said segments being grouped according to topics, said method comprising the steps of providing an announce routine for placing said terminal in a command mode for at least a predtermined set of commands, said routine displaying to a student both an announcement that a new topic is about to begin and a notice that the student has an opportunity to select for execution a command from among commands of said predetermined set, said set including at least one address-generic transfer command for transferring program execution to a different location in said database, and calling said routine at predetermined topic locations in said material.