Bridging the gap between analysis and design: improving existing driver interfaces with tools from the framework of cognitive work analysis

Two studies of train driving are presented, both within the framework of cognitive work analysis. In the first study, the modelling tool abstraction–decomposition space is adapted to routine conditions, making the analysis more representative for normal procedures. A major contribution to these analyses was the use of the method for ‘collegial verbalisation’. One particular advantage with this method over other verbalisation methods is that it supplies the analysts with data that contain much more information, but not at the expense of being more subjective. On the contrary, this method produces think-aloud protocols from video-recordings that do not have to be interpreted by the researcher. From these analyses, it was possible to distinguish information that is an intrinsic part of the train driver task from information that is dependent on the configuration and design of the current support system. The analyses show that the driver works in three rather separate time intervals with a long-range, a short-term and an immediate sense of perspective. The driver switches between these while travelling between two stations. Based on these behaviour-shaping constraints, a prototype of a planning area of a driver interface was developed, making feed-forward planning possible for the driver. Four design iterations were completed, using a user-centred system design (UCSD) approach. Early tests show that the planning area of the interface supports the feed-forward decision strategy used by drivers who prefer an active driving style. However, the driver group also made substantial changes in the design, indicating that UCSD is an efficient tool in order to capture user competencies, and to bridge the gap between analysis and design.