S.: Assessing the Usability of an Interactive Information Visualization Method as the First Step of a Sustainable Evaluation

Gravi++ is a visualization method that is designed to support psychotherapists in their work with anorectic girls. During the therapy complex and time dependent data have to be analyzed. Statistical methods cannot be used in this context, and visualizations seem to be a viable alternative. Gravi++ is based on a spring metaphor. It can represent time dependent data easily. There is still too little systematic and empirically validated knowledge to support the design of such information visualizations. Therefore, extensive evaluation is necessary. The evaluation process is composed of two steps – a usability study and the evaluation of the Gravi++ method as such. The following paper describes the usability study. Methods used were usability inspection / guideline review, heuristic evaluation and focus groups. Heuristic evaluation was a very valuable method for identifying usability problems. Focus groups did not yield very much additional factual knowledge but gave important insights about the subjective importance of usability problems

Visual exploration of time-oriented patient data for chronic diseases: Design study and evaluation

Abstract. Medical care, particularly for chronic diseases, accumulates a huge amount of patient data over extensive time periods that needs to be accessed and analyzed accordingly. Information Visualization methods hold great promises in turning data deluge into improved quality of medical care. Yet, patient data management systems mostly provide documents, form-based displays, or static visualizations. We present a design study of an interactive visualization system, called VisuExplore, to support long-term care and medical analysis of patients with chronic diseases. VisuExplore offers interaction techniques for effective exploration of time-oriented data and employs simple, but intuitive visualization techniques. It was developed in close cooperation with physicians. We conducted two user studies with nine physicians and 16 students, which indicate that our design is useful and appropriate for particular tasks