This report describes the methods and results associated with Task B: Preliminary Assessment of Visual Symbols. The purpose of Task B is twofold: (1) it identifies credible procedures, heuristics, and principles for the joint use of visual, auditory, and tactile information to present in-vehicle messages, and (2) it defines message characteristics that should guide symbol design. Defining these characteristics and their interactions helps to identify design tradeoffs and provides the basis for future design guidelines and tools. The methodology employed to complete Task B included: refining a list of previously generated IVIS messages, conducting a review of the literature relevant to sensory modality, evaluating the IVIS messages using a sensory modality decision tool, defining messages according to their contextual characteristics and information processing elements (IPEs), clustering messages according to their contextual characteristics, grouping those clusters to identify general design categories, and examining the IPEs and design tradeoffs within each cluster and category. Through the process of devising these design tools and decision aids and analyzing the list of relevant IVIS messages, we developed the following conclusions: (1) a review of existing literature regarding visual, auditory and tactile information presentation provided numerous general principles for modality selection, which was the basis for an effective sensory modality decision tool, (2) classifying IVIS messages according to ITS technologies and general functions is insufficient for providing effective design guidelines, (3) understanding the driving context under which IVIS messages are presented is critical for successful design guideline development, (4) the IPEs associated with an IVIS message can successfully be used to develop the design guidelines that consider the perceptual, memory, and motor control limits of the driver, (5) the cluster analysis technique provides a powerful tool to focus future analyses on a meaningful subset of possible combinations of contextual characteristics and IPEs, (6) the tools and decision aids developed as part of Task B have provided the project team with a solid analytical foundation to begin guideline development in Task C of this project, and (7) a key challenge associated with Task C will be to integrate the information provided in this report and develop clear, relevant, and easy-to-use design guidelines for in-vehicle icons. (Author/publisher)
Abstract