A method and apparatus for a computer-based teaching system includes modifying a text file by inserting a first predetermined character at a first end of a first selected information element, and also inserting a second predetermined character at a second end of the first selected information element. A blank box is created in an area defined by the first and second predetermined character. The blank box replaces the first selected information element. Data is stored in a memory, with the data representing the first selected information element. A user interface is provided, which enables selective display of either the blank box or the first selected information element.