A task analysis approach to the visualization of geographic data

Over the last decade two trends have been apparent; the first an increasing complexity and volume of environmental data and the second a rapid development of computer technology. The first trend would be overwhelming if it were not for the second but this convergence of the need for information tools and the potential to provide them has also dramatically increased the need to provide the human user of such systems with intuitive software support. Scientific visualization is an emerging discipline which holds considerable promise for geographers examining diverse, n-dimensional data sets. Incorporating scientific visualization systems (SVSs) into the set of tools available to geographers requires a thoughtful approach to visual design and software requirements. Traditional approaches to requirements focus on functions or data, often leaving the human user to deal with cumbersome, ineffective software. As visual displays are of optimal support only when they directly support geographer's tasks, a task analysis methodology was developed and tested in this research with the objective of producing more intuitive designs and more user-oriented visualization software requirements. The task analysis methodology developed and modified through this research was based on an examination of the fundamental concepts of task analysis, work on data classification in cartography and visualization, and research on visual operators or visual primitives. An initial task model was tested by the author and two independent designers in seven real-world cases with scientists from the U.S. Geological Survey and the Colorado State Drought Assessment Group. The research produced two results. First, a final task analysis methodology comprising a task structure, task model, design model, and a list of primary visual operators. Second, a set of software requirements was developed through the implementation of designs created from the task analyses. The conclusions drawn from the research indicate that visualization techniques can indeed be of assistance to geographers but that the functions of generic SVSs must be tailored and enhanced, as indicated by the requirements list, for their full value to be realized.