LAYERED PROTOCOLS - HANDS-ON EXPERIENCE

An assessment is presented of the benefits and limitations of the Laye red Protocols (LP) model for the analysis and design of user interface s in the held of consumer electronics. In the assessment a user interf ace of an existing digital audio recorder which is only partly in line with the LP model is compared with an interface designed according to the model. The observed differences in usability between the two inte rfaces are mainly caused by deviations from the LP model. It turned ou t that especially the learnability of an interface is positively influ enced by a layered organization of user-system interaction in combinat ion with high-quality E- and I-feedback and optimum similarity between interaction protocols. (C) 1996 Academic Press Limited