This study focused primarily on two types of computer interfaces and the differences in academic performance that resulted from their use; it was secondarily designed to examine gender differences that may have existed before and after any change in interface. Much of the basic research in computer use was conducted with command line interface (CLI) based computers and their Video Display Terminal based relatives that use the keyboard as their primary and often only initial input device. Today, graphical interfaces (GUIs), with the mouse or light-pen as the primary interface device, are becoming the rule in computer use. Thus, the question arises whether research on learning completed with command line interfaces is transferable to the graphical interface situation. Any changes of interface could have significant effects on how users use and how easily they can learn to use computers. The change from CLI to GUI also encompasses a change from the more abstract representations of actions to a more concrete representation both in file manipulation and information preparation and presentation. The final grades of students enrolled in either of two introductory computer science classes were analyzed from the fall semester of 1987 through the fall semester of 1990. During this time period, instruction was changed from CLI-based to GUI-based instruction. The findings do not indicate any gender differences based on interface and do not indicate that there is any statistically significant difference between the interfaces used. The appendix provides a historical analysis of computer interfaces. (30 references) (DB)