Selecting System Functionalities for Interface Evaluation

Abstract

Software developers are frequently required to evaluate the usability of produces they design. Limited resources often prevent them from performing a complete interface evaluation prior to product release. In these instances a relatively standard approach is to identify a few functionalities on which to focus evaluation efforts. This paper proposes a three-phased methodology for selecting this “short list” of functionalities. In Phase 1 a functional-level goals, operator., methods, selection rules (GOMS) model representing required user-system interaction tasks is developed. In Phase 2 functionalities are identified, which serve as candidates for evaluation. Task descriptions developed during the initial phase facilitate completion of Phase 2. In Phase 3 the functionality short list is derived. The methodology is applied to the Information Engineering Facility^TM, a computer-aided software engineering tool developed by Texas Instruments. Implications of implementing the methodology are discussed.