Examples of computer programs illustrate how instructors can introduce students to geographic concepts and models while creating a thinking environment in the classroom. The programs are designed to assist students in computational tasks and to provide both graphic and numeric output which will be stimulating. A population pyramid program appropriate for use in a college level human geography course exemplifies poor interactive programming: there are no graphics to reinforce student responses and no opportunity for students to vary input or programming. The second program, suitable for use at any grade level, charts population growth rates of the United States and other countries. It is a good example of interactive programming in that it provides adequate instructions and questions to lead students into the exercise, all instructions and questions are displayed on the screen, error checks are built into the program, and the program allows a wide variety of inputs. The third program, on solar calculations, contains two significant interactive aspects: questions and student responses are displayed and several input options are available. The remaining program, a climatic water balance model for college level courses, demonstrates how instructors can adapt existing programs to increase student interaction. Accompanying figures illustrate video displays for each of the computer programs discussed. (LP)