This case study examines how one technique, the use of logging data, was used throughout the design of a new text editor which is measurably easy to learn and easy to use. This interface, called Eve, was to be measurably easy to learn and easy to use for both novice and experienced computer users. Eve would also take advantage of the keyboard layout in Digital's VT200 series terminals. A variety of human factors techniques were used throughout the editor design process, including experimentation, rapid prototyping, iterative design, and logging. This paper describes how logging data collected from a variety of text editors was used throughout the design of Eve.
Benchmark tests show that the resulting editor is measurably easy to learn and easy to use.
Logging Data Existing logging data from five different editors was used during the design of Eve. All of the editor data included totals for either keystrokes or command frequencies, as described below. The WPS and EPT data also included the frequencies of transitions between keystrokes. When the logging data was collected, CCA Emacs contained 206 commands, but did not include an editor extension language. The editor contained 74 commands, and the logging sample contained over 22,000,000 keystrokes collected over three weeks.